Abstract:
A network analysis system obtains parameter data generated by telecommunications network equipment, in which the parameter data represents operational parameters of the network. The network analysis system processes the parameter data to generate symptom data from test procedures that are applied to the parameter data. Fault data is generated that is representative of faults that may have occurred, on the basis of the symptom data and relationship data representative of the relationship between the symptom data and the faults. The relationship between a symptom and a fault represents likelihood of the symptom being caused by the fault. The system also generates occurrence data that is representative of faults that probably have occurred, on the basis of the fault data.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a network analysis system and method. 
     BACKGROUND OF THE INVENTION 
     Telecommunications systems include sophisticated electronic switching equipment which is able to provide extensive data on the state and performance of the equipment and other aspects of a telecommunications system. Mobile telecommunications systems, in particular, are subjected to a wide variety of operating conditions which depend to a substantial extent on the movement and use of mobile telecommunications stations. The operating conditions of a mobile system include an unpredictable element and can give rise to a variety of different faults which need to be detected. The equipment of mobile telecommunications systems and, in particular, the base stations used in the systems, generate a considerable amount of data from which faults can be determined. It would be advantageous to be able to monitor a telecommunications network by accessing data which may be pertinent to fault determination and then analyse that data to detect faults. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention there is provided a network analysis system including: 
     means for obtaining parameter data generated by equipment of a telecommunications network, said parameter data representing operational parameters of said network, 
     means for processing said parameter data to generate symptom data from test procedures applied to said parameter data, and 
     means for generating fault data, representative of faults which may have occurred, on the basis of said symptom data and relationship data representative of the relationship between said symptom data and said faults. 
     Advantageously, said fault data may further represent the likelihood of said faults having occurred. 
     Preferably said system further includes a graphical user interface for establishing and adjusting said relationship data. 
     Preferably said system further includes means for generating occurrence data, representative of faults which probably have occurred, on the basis of said fault data. 
     Preferably said occurrence data generating means applies predetermined rules to said fault data to generate said occurrence data. Preferably said occurrence data generating means compares fault data associated with a plurality of said equipment having a predetermined relationship to generate said occurrence data. Depending on said relationship, the occurrence data generating means may remove from consideration fault data for one of said plurality of said equipment. 
     In accordance with the present invention there is also provided a network analysis system including: 
     means for obtaining parameter data generated by equipment of a telecommunications network, said data representing operational parameters of said network, 
     means for processing said parameter data to generate fault data representative of faults which may have occurred, and 
     means for generating occurrence data representative of faults which probably have occurred on the basis of said fault data. 
     The present invention also provides a network analysis method including: 
     obtaining parameter data generated by equipment of a telecommunications network, said parameter data representing operational parameters of said network, 
     processing said parameter data to generate symptom data from test procedures applied to said parameter data, and 
     generating fault data, representative of faults which may have occurred, on the basis of said symptom data and relationship data representative of the relationship between said symptom data and said faults. 
     The present invention further provides a network analysis method including: 
     obtaining parameter data generated by equipment of a telecommunications network, said data representing operational parameters of said network, 
     processing said parameter data to generate fault data representative of faults which may have occurred, and 
     generating occurrence data representative of faults which probably have occurred on the basis of said fault data. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred embodiment of the present invention is hereinafter described, by way of example only, with reference to the accompanying drawings, wherein: 
     FIG. 1 is a block and flow diagram of a preferred embodiment of a network analysis system; 
     FIG. 2 is a schematic diagram illustrating storage of performance indicators in a data store of the system; 
     FIG. 3 is a diagram of a main menu of the system; 
     FIG. 4 is a block and flow diagram of a diagnostic inference network of the system; 
     FIG. 5 is a diagram of a decision table display of the system; 
     FIG. 6 is a diagram of another decision table display of the system; 
     FIG. 7 is a block and flow diagram of a diagnostic and recommendation expert system of the system of FIG. 1; and 
     FIG. 8 is a flow diagram for the diagnostic and recommendation expert system of FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A network analysis system  2 , as shown in FIG. 1, is a computer based system which includes a data storage system  4 , a diagnostic inference network (DIN)  6 , a diagnostic and recommendation expert system (DRES)  8  and an X-Windows based user interface. Although a software implementation on a computer workstation, such as Sun Microsystems Sparc Station  5  running Unix, is described hereinafter, the analysis system  2  can be implemented using specific hardware components or in software, or using a combination of both. The software of the system  2  has been written in C++ and for the DRES  8 , the code was written using the OPS  5  rule language which compiles to C. 
     Network performance data is automatically generated by equipment of a network  10 , such as the base station of a mobile telecommunications network, and is automatically collected by a data collection system  12  and provided to the data storage system  4 . The data collection system  12  may be provided by a Common Application Platform (CAP) which is a software package that interfaces with the analysis system  2  and the equipment of the network  10 . The CAP schedules the execution of data collection and post-processing programs on the equipment, and can also be used to schedule execution of modules of the analysis system  2 . The CAP includes commands that can be executed to access the network data automatically from the equipment and load it into the data storage system  4  of the analysis system  2 . For a mobile telecommunications network, the performance data collected may include: 
     MT data generated by mobile telephone exchanges in order to describe the configuration of the network (e.g. cells, voice channels, control channels and inter-cell relationships); 
     CTS (cell traffic statistics) data generated by mobile telephone exchanges and representative of summary statistics on mobile telephone traffic (e.g. accesses, drop-outs and handoffs) over a predetermined measurement period, typically four to eight hours; 
     RES (radio environment statistics) data generated by mobile telephone exchanges and representative of summary statistics on the radio performance of an exchange, such as signal strength, signal to noise ratios over a predetermined measuring period, typically four to eight hours; and 
     RDR (radio disturbance recording) data generated by mobile telephone exchanges and representative of statistics on radio interference in the network over a predetermined measurement period. 
     The data storage system  4  establishes a database for the network performance data, whilst also providing tools to access the data and a description of the network configuration. The network data represents a number of different network performance indicators which correspond to network objects, such as telephone exchanges, cells of a mobile cellular network, base stations or communications channels. A list of the network performance indicators which can be processed by the analysis system  2  for a mobile telecommunications network is provided on pages 16 to 19. Data for each network object is stored in a hierarchical representation with the data for each performance indicator for a network object being stored in a matrix relationship, as shown in FIG.  2 . For each network object  14  a row  16  of performance data represents the data collected over one day for a number of performance indicators, whereas a column  18  includes a chronological history of data collected for one performance indicator for an object  14 . The user interface of the analysis system  2  provides main menu  20 , as shown in FIG. 3, which provides the user with access to tools for accessing the data by selecting the following command buttons on the interface  20 : 
     1. Purge data  22  allows data to be selectively removed. 
     2. Browse data  24  allows the collected network data to be displayed and scrolled through for different network objects, and also allows data to be graphically plotted for any performance indicator for any object and for any time period, with information concerning control limits for network data and special events which have occurred. 
     3. Reset control limits  26  allows control limits for network performance indicators to be reset. The control limits for an indicator provide upper and lower limits (UCL and LCL) on the random variation expected for the indicator. The limits can be used to determine when selected events occur and for defining symptoms used by the DIN  6 . The reset control limits procedure also enables the control limits to be checked by applying statistical comparisons to new limits and old limits to generate a report specifying which control limits may need to be reset for network objects and their performance indicators. 
     4. Event log  28  allows a log to be made for any known disturbance of a network object which might otherwise be perceived as a fault by the DIN  6  or the DRES  8 . 
     Once data has been collected and stored in the data storage system  4 , the data can be applied to the DIN  6  by selecting the run DIN command button  30 . 
     The DIN  6  is a program which performs a preliminary diagnosis of problems in the telecommunications network by analysing network objects, such as cells or exchanges, in isolation. The DIN  6 , as shown in FIG. 4, uses an inference engine  32  to detect changes in the network performance indicators of network objects using decision tables  34  for each object, and then suggesting the cause of the changes in a DIN report  36  generated by the inference engine  32 . A DIN report  36  contains the results of applying a decision table to network performance data of a network object for a particular date. The reports  36  are saved in unformatted data files which can be examined and formatted as required using a DIN browser module  37 , selected by the browse DIN report button  38 , to produce formatted DIN reports  40 . 
     The DIN  6  is able to monitor large amounts of network performance data and quickly diagnose possible faults indicated by the data. This is achieved by constraining the complexity of the reasoning used to diagnose faults. The faults are each characterised by a pattern of symptoms, which are determined from the performance data for a network object. The patterns arc each represented by a mathematical formula based on the relationships between a fault and its symptoms. This produces a decision network of symptoms leading to faults which is established by telecommunications experts and represented in the decision tables  34 , as described below. This in contrast to neural network techniques which use training algorithms to establish a decision network and implicitly encode fault symptom relationships as weights in the network based on a set of training examples. 
     A decision table  34  is represented graphically on the user interface as shown in FIG. 5, and retains information concerning a list of symptoms  42  to be monitored by the DIN  6 , a list of faults  44  which can be inferred by the DIN  6  and a set of relationships  46  between the faults  44  and the symptoms  42 . The faults  44  are allocated respective columns of the decision table  34 , and the symptoms are allocated respective rows of the decision table  34 . A relationship between a fault  44  and a symptom  42  is specified at the intersection for the column of the fault  44  and the row of the symptom  42 . The table  34  is used by the DIN  6  to monitor possible problems, i.e. symptoms  42 , in a network object, and to suggest likely causes of these problems, i.e. faults  44 . 
     A symptom  42  is the result of a test applied to a network performance indicator, such as “traffic overflow greater than 10%”. A symptom is determined for a network object at a particular date i by extracting the value of the indicator x i  on that date, and applying the symptom&#39;s test to that value. If the indicator value is unavailable at that date, then the symptom value is unknown, otherwise the symptom value is true or false. 
     A number of different tests can be applied to the performance indicators and the tests are normally one of four main types: threshold tests; difference tests; moving average tests; and control limit tests. For example one of the following tests may be selected for a symptom: 
     X i &lt;{threshold} 
     x i &lt;={threshold} 
     x i ={threshold} 
     x i &gt;{threshold} 
     x i &gt;={threshold} 
       100 *(x i −x i−1 )/x i−1 &gt;{threshold} 
     − 100 *(x i −x i−1 )/x i−1 &gt;{threshold} 
     x i &gt;mean(x i−1 )+{n} * std-dev(x i−1 ) 
     x i &lt;mean(x i−1 )−{n} * std-dev(x i−1 ) 
     x i &gt;upper control limit 
     x i &lt;lower control limit 
     x i outside control limits (upper or lower) 
     x i within control limits (upper &amp; lower) 
     Faults  44  are the possible causes of the symptoms  42 , for example “faulty transceiver”. The network objects each have their own set of faults which can be selected for inclusion in the decision table  34 . The DIN  6  rates the likelihood of each fault for a network object based on the status of each symptom that is related to the fault. 
     The symptoms may each be caused by many faults, and similarly each fault may cause a number of symptoms. The more active symptoms there are that can indicate a fault, the more likely it is that the fault exists. The DIN  6  accumulates evidence for each fault by looking at the values of the symptoms that are related to the fault. There are five types of relationships  46  which a symptom  42  can have to a fault  44 , and these are: positive; negative; necessary; prohibited; and null. 
     A positive relationship  50 , as indicated on the user interface by a white circle with a black circle inside it, means that when the symptom is active (i.e. true), the fault is a possible cause. A negative relationship  50 , as indicated by a white circle with a small white circle inside of it, as shown in FIG. 6, means that when the symptom is active, the fault is unlikely to be the cause. A necessary relationship  54 , as indicated by a dark circle, means that the symptom must be active for the fault to be considered active. A prohibited relationship  56 , as indicated by a white circle, means that if the symptom is active then it cannot be caused by the fault. A null relationship  58 , as indicated by a small black dot, means that the fault is not indicated by the symptom in any way. Positive relationships can be used to trigger faults whilst negative relationships can be used to filter faults. 
     The likelihood of a fault being active is determined by looking at the status of the symptoms to which it is related. For a fault to be active, all of its necessary symptoms and none of its prohibited symptoms must be active. If it has no necessary relationships to symptoms, then at least one positive symptom must be active for the fault to be active. The DIN  6  decides that a fault is active if the number of active positive symptoms is greater than 0 and there are no necessary symptoms inactive and no prohibited symptoms active. The DIN  6  generates a fault likelihood weighting which is: 
     0, if there are inactive necessary symptoms, active prohibited symptoms or no active positive symptoms; or 
     the number of active positive symptoms, if there are no unknown symptom values or negative symptoms; or 
     the number of active positive symptoms divided by the sum of the active symptoms and inactive symptoms, and half the number of unknown symptom values. 
     If a fault is active, then it is given a ranking based on the likelihood weighting: 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 &gt; = 0.66 
                 very likely 
               
               
                   
                 &gt; = 0.33 &amp; &lt; 0.66 
                 likely 
               
               
                   
                 &gt; 0 &amp; &lt; 0.33 
                 possible 
               
               
                   
                 0 
                 unlikely 
               
               
                   
                   
               
             
          
         
       
     
     Using the decision table  34  shown in FIG. 6 for a network object with the following network performance indicators: 
     
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Indicator 
                 Value 
                 LCL 
                 UCL 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Ind1 
                 1000 
                 200 
                 800 
               
               
                   
                 Ind2 
                 7 
                 0 
                 10 
               
               
                   
                 Ind3 
                 2 
                 1 
                 8 
               
               
                   
                   
               
             
          
         
       
     
     will cause the DIN  6  to generate the result that faults f1 and f2 are very likely, whereas f3 and f4 are unlikely. The result occurs because the first three symptoms  60  are true and the last two symptoms  62  are false. The likelihood ranking for f1 is 1.0 (very likely), for f2 is 0.67 (very likely) and for f3 and f4 is 0 (unlikely). 
     Selecting the DIN editor command button  62  invokes a DIN edit module  64  which allows the decision tables  34  to be edited as desired for each network object. DIN edit  64  provides a graphic user interface which allows the user to point to elements in a table  34  and select using a pointing device how the user wishes the table to appear. For example, symptom/fault relationships  46  are specified by pointing and clicking on a symptom/fault intersection. First a white circle with an inner black circle will appear and if the user clicks again, the circle will be entirely black. A further click brings up a white circle and then another click will bring up a white circle with a small white circle inside of it. A final click produces the small black dot which indicates the null relationship. Movement through the different relationships  46  is circular. By clicking on either a fault label  44 , network performance indicator label  64  or test label  66 , a user is presented with a pop-up window from which a number of different faults, indicators or tests can be selected. The decision table  34  can then be allocated to an object of the network. Default decision tables  34  can also be set using a set default DIN tables procedure by selecting the set default DIN tables button  70 . The DIN reports  36  and  40  provide the details of the objects which have been analysed, the decision tables which have been used, and the type of performance data which has been used. The data is normally specified by a date or reference to a data file name. Symptoms are described by their status (active, inactive or unknown) and faults are described by their status (very likely, likely, possible or unlikely) together with a summary of the evidence for the fault. 
     The DRES  8 , as shown in FIG. 7, includes a rule-based expert system  70  which uses the raw DIN reports  36  and data accessed from the data storage system  4  concerning network objects to generate raw reports  72  which reduce the list of possible faults to a list of confirmed faults. The DRES  8  also includes a DRES browser module  74 , which is activated by selecting the browse DRES report button  76 , to allow the raw DRES reports  72  to be displayed and reformatted into user defined formatted DRES reports  78 . The expert system  70  is invoked by selecting the run DRES button  80  from the main menu  20 . 
     The DRES expert system  70  analyses network objects in combination using a day&#39;s network performance data at a time to provide a detailed level of fault diagnosis. On initiation, DRES  8  accesses all of the data concerning problem network objects from the DIN  4  during an initial procedure  90 , as shown in FIG.  8 . The DRES  8  then enters an investigation procedure  92  where the faults are investigated for each object identified by the DIN  6  as containing potential faults. The investigation procedure  92  first accesses external information concerning a network object using post-processing programs to further confirm particular faults specified by the DIN  6 . The post-processing programs are programs which are available for accessing the performance data generated by an exchange so as to produce consolidated reports on the performance data. For a mobile cellular network, information is accessed to determine one channel higher, one channel lower, Voice Channel (VC) uplink interference and faulty VC, every second channel low and various faults in order to collect further evidence for the following faults: reduced VC transmitter (TX) power; fault in TX path at base; faulty VC transceiver; faulty VC transceiver; VC uplink interference; loss of PCM link to exchange; clicking transceiver; incorrect Power level (PL) value; and reduced VC IX power. 
     The investigation procedure  92  also accesses and checks information concerning related network objects. For a mobile cellular network, each base station may establish one or more cells which may overlap to some extent with adjacent cells. A base station is connected to a telephone exchange of the network for the switching of calls and the cells of a station can form a group known as a cell cluster, which can share carrier frequencies. An ncell is a neighbouring cell which can be used to receive a handoff when the current cell must force a call in progress to handoff to another cell. A dcell is a nearby cell to the current cell which is used when a cell receives call attempts that it is unable to handle, and the station or exchange needs to redirect these calls to one or more nearby cells. An nocell is an ncell that is on a different exchange to the current cell. The following table shows faults and ncell/dcell/nocell information that is obtained by the investigation procedure  92 . For instance if DIN  6  has indicated that there may be a loss of PCM link to the exchange then DRES  8  will check whether there has been an increase in DRVCC or TRAFOV in the ncell of this cell. A further rule checks that the ncell/dcell evidence is higher than a preset threshold (TRAFOV/DROPHO&gt;1% and VCDESF/INSTXQ&gt;2%o), as a significance test on input data. A description for the alphanumeric acronyms used for the network performance indicators is provided on pages 16 to 19. 
     
       
         
               
               
               
             
           
               
                   
               
               
                 Fault 
                 Type of Cell 
                 Indicator(s) 
               
               
                   
               
             
             
               
                 Loss of PCM link 
                 ncell/nocell 
                 DRVCChigh, 
               
               
                   
                   
                 TRAFOVhigh 
               
               
                 Loss of PCM link 
                 dcell 
                 TOTACChigh 
               
               
                 Fault in CC redundancy switch 
                 ncell/nocell 
                 TRAFOVhigh 
               
               
                 Special event (high) 
                 ncell/nocell 
                 TRAFOVhigh 
               
               
                 Special event (low) 
                 ncell/nocell 
                 HOFONP&gt;1 
               
               
                 Misdirected Rx antenna 
                 ncell/nocell 
                 TOTACChigh 
               
               
                 Base station hardware fault 
                 ncell/nocell 
                 TRAFOVhigh 
               
               
                 Faulty SS receiver (high) 
                 ncell/nocell 
                 INSTXQhigh 
               
               
                 Faulty SS receiver (low) 
                 ncell/nocell 
                 DROPHOhigh 
               
               
                 Faulty Rx antenna 
                 ncell/nocell 
                 TRAFOVhigh 
               
               
                 Loss of PCM link 
                 ncell/nocell 
                 TRAFOVhigh 
               
               
                 Fringe cell cover problem 
                 ncell 
                 No. of cells &lt;3 
               
               
                   
               
             
          
         
       
     
     After accessing the external information and the related object information, DRES  8  then uses the investigation procedure  92  to perform a detailed network object analysis using three different types of rule groups: problem not confirmed, further tests within an object and general versus specific. Examples of the problem not confirmed group for a mobile cellular network are as follows: 
     If there is indirect evidence for a “loss of PCM link to exchange” or “base station hardware fault”, then check whether this evidence comes from cells within the same base and remove it if it does not; 
     If there is no indirect evidence to support the fault “loss of PCM link to exchange”, “fault in CC redundancy switch” or “faulty SS receiver low” then remove this fault; and 
     If there is a fault “incorrect interexchange handoff data” and the cell is not a border cell, then remove this fault. 
     Examples of further tests within a network object, for a mobile telecommunications cell are as follows: 
     If there is a fault “faulty Rx antenna” then check whether HOFFI and HOFFO are about 50%, and add it as additional evidence if it is; 
     If there is a fault “faulty SS receiver low” then check whether HOFFO is greater than HOFFI and add it as additional evidence if it is; 
     If there is a fault “incorrect interexchange handoff data” then check whether DRVCC is less than 10, if it is not remove the evidence; 
     If there are faults “special event high traffic”, “cell capacity problem”, “loss of VC transceiver” then check whether TRAFOV is greater than 5%, if it is not remove the evidence; and 
     If both a “faulty Rx antenna” and a “misdirected Rx antenna” are indicated in the same cell, then remove the “misdirected Rx antenna”. 
     A general versus specific rule has the following format: if there is a fault “X” and there is a fault “Y” and that fault has no indication of “Z” then remove fault “Y”. For example, if there is a fault “loss of VC transceiver”, and there is a fault “faulty VC transceiver”, and there is no evidence of _G.BS25 high or _G.VCI90 high, then remove the fault “faulty VC transceiver”. 
     The DRES  8  then executes a compare procedure  94  which accesses a group of rules to compare related network objects. The group of rules check whether indirect evidence for one fault is also direct evidence for another fault. For instance, if there is a cell A that has some indirect evidence X from cell B and in cell B that evidence is the only piece of evidence then remove faults associated with this evidence X from cell B. For example, if cell A has the fault “loss of PCM link” with indirect evidence of high TRAFOV from cell B, and there is any faults in cell B with high TRAFOV as their only evidence, then remove those faults. An exclusion procedure  96  is then used to exclude false positives by using a group of rules that checks whether performance indicators relate to aspects of the network which can be misconstrued as faults, such as that which may be caused by an overlayed cell, a small cell or use of a low noise amplifier to extend cell range, and are abnormal but valid network conditions. For example, if a cell has high DROPHO, high VCDESF, high _G.VCI90 and high REGATT, then the cell may have a low noise amplifier, which is not a fault. 
     The final procedure  100  of DRES  8  invokes modules to retrieve recommendations for dealing with the remaining faults and write the raw DRES reports  72  out to a file. The modules collect all of the evidence and information concerning the remaining faults and their associated network objects. The DRES reports  72  generated include a summary report which contains the number of occurrences of faults allocated to a network object, and detailed reports which list faults identified by DRES  8  and persistent faults. The DRES browse procedure  74  includes an option to select a persistence module which allows a user to create or modify a persistence file  102  which includes symptoms defined to be persistent for nominated network objects. A user can associate tests to be applied when a persistent symptom is found to be active to try and override the symptom. If all of the symptoms of a fault are persistent and neither of the associated tests succeed, then the fault is defined to be persistent and is placed into a persistent fault section at the end of a DRES report  72 . A user can set a date on which a persistence test for a symptom is no longer applied. 
     The rules described above for the DRES  8  are indicative of the types of rules required to analyse fault data and we have described the overall organisation of the rule base. The form and detail of these rules depends almost entirely on the technology and implementation of the network to be analysed. Since networks, their performance and method required for analysis depend upon the technology used, design criteria and regional characteristics, the DRES analysis rules must be tailored to the particular details of the network concerned and cannot be circumscribed without detailed network knowledge. 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 MOBILE NETWORK PERFORMANCE INDICATORS 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 REGATT 
                 Registration Attempts 
                   
               
               
                 TOTACC 
                 Total call accesses 
               
               
                 MSORG 
                 MS Originating Traffic (%) 
               
               
                 MSTERM 
                 MS Terminating Traffic (%) 
               
               
                 DRVCC 
                 Directed Retry Due to Voice Channel Cong. (%) 
               
               
                 PAGE1 
                 Response to first page (%) 
                 (No longer used) 
               
               
                 TRAFOV 
                 Traffic Overflow (%) 
               
               
                 VCSZE 
                 VC Seizures 
               
               
                 TOTLOC 
                 Total number of locatings 
               
               
                 LOHOFA 
                 No. of locatings per handoff attempt 
               
               
                 HOFAIL 
                 Failed handoffs (%) 
               
               
                 HOFFO 
                 Total number of handoffs out 
               
               
                 HOFONP 
                 Handoffs to non-primary cell (%) 
               
               
                 HOFAILO 
                 Failed/Unsuccessful Handoffs out (%) 
               
               
                 HOFFI 
                 Total number of handoffs in 
               
               
                 HOFINP 
                 Handoffs in as non-primary cell (%) 
               
               
                 HOFAILI 
                 Failed/unsuccessful Handoffs in (%) 
               
               
                 VCDESF 
                 VC Designation Failures (%) 
               
               
                 DROPHO 
                 Dropouts at handoff (%) 
               
               
                 INSTXQ 
                 Dropouts due to insufficient Tx Quality (%) 
               
               
                 CALLDO 
                 Call Dropouts (%) 
               
               
                 HINSTX 
                 Handled Insufficient TX Dropouts (%) 
                 (No longer used) 
               
               
                 CPROGDO 
                 Calls in Progress Dropout (%) 
               
               
                 DRUPR 
                 Directed Retry due to Unknown Page Response 
               
               
                 UPRREJ 
                 Unknown Page Response Rejection Ratio 
               
               
                 HORATIO 
                 HOFFSI/HOFFSO 
               
               
                 HOFFITOT 
                 Total unsuccessful HO in 
               
               
                 HOFFOTOT 
                 Total unsuccessful HO out 
               
               
                 A&lt;SSACC 
                 Accesses &lt; SSAC 
               
               
                 VCSZCII 
                 VC seize rejected C/I in 
               
               
                 VCSZCIO 
                 VC seize rejected C/I out 
               
               
                 ACCMULT 
                 Multiple accesses 
               
               
                 ACCALL 
                 All accesses (including those less than SSACC) 
               
               
                 SATFOUT 
                 SAT fail out 
               
               
                 SATFIN 
                 SAT fail in 
               
               
                 R&lt;SSREG 
                 Registrations &lt; SSREG 
               
               
                 _ML.1 
                 Local control activated on deblocked CHM 
               
               
                 _ML.10 
                 Return from local control made 
               
               
                 _ML.70 
                 PMU alarm SWR too high 
               
               
                 _ML.182 
                 Illegal Station Class Mark 
               
               
                 _ML.208 
                 Measured request outside line 
               
               
                 _ML.220 
                 Failed VC start at handoff 
               
               
                 _ML.221 
                 Failed VC start at handoff 
               
               
                 _ML.222 
                 Disc poor transmit quality 
               
               
                 _ML.223 
                 SAT verification Failure 
               
               
                 _ML.224 
                 100 VC start failure 
               
               
                 _ML.225 
                 Handoff start failure 
               
               
                 _ML.226 
                 65% VC start failure 
               
               
                 _ML.254 
                 26VBAT &lt; 25.4V 
               
               
                 _ML.257 
                 Rx-board + 12V voltage out of range 
               
               
                 _ML.261 
                 AIO-unit +5V reference out of range 
               
               
                 _ML.263 
                 A-channel for CC diversity error 
               
               
                 _ML.264 
                 B-channel for CC diversity error 
               
               
                 _ML.266 
                 LOL1 out of range 
               
               
                 _ML.267 
                 A-channel for VC diversity error 
               
               
                 _ML.268 
                 B-channel for VC diversity error 
               
               
                 _ML.307 
                 Modem hardware or software failure 
               
               
                 _ML.314 
                 FGTX synthes lock failure detected 
               
               
                 _ML.322 
                 PMU detected SWR from antenna too high 
               
               
                 _ML.323 
                 Multi coupler failure on A-channel 
               
               
                 _ML.324 
                 Multi coupler failure on B-channel 
               
               
                 _ML.325 
                 Multi coupler failure on A &amp; B-channels 
               
               
                 _ML.338 
                 Minor output power regulation loop failure 
               
               
                 _ML.341 
                 PA-unit output regulation failure 
               
               
                 _ML.343 
                 PA-unit failure detected 
               
               
                 _ML.346 
                 PA-unit output regulation failure (PALEVEL too high) 
               
               
                 _ML.347 
                 PA-unit output regulation failure (PALEVEL too low) 
               
               
                 _ML.348 
                 PA-unit output regulation failure (output power too high) 
               
               
                 _ML.349 
                 PA-unit output regulation failure (output power down 1 dB) 
               
               
                 _ML.350 
                 Too high SWR on PA-unit output 
               
               
                 _ML.351 
                 One of two PA-unit temperature detectors faulty 
               
               
                 _ML.352 
                 26V regulator board faulty 
               
               
                 _ML.353 
                 Overtemperature on PA-unit detected 
               
               
                 _ML.356 
                 AIO hardware failure 
               
               
                 _ML.359 
                 FGRX-unit synthes lock failure 
               
               
                 _ML.361 
                 Modem hardware or software failure 
               
               
                 _ML.364 
                 S/W Exec. queue nearly full 
               
               
                 _ML.377 
                 Reference osc alarm in connected CHM 
               
               
                 _G.%&lt;ACC 
                 % of non-compensated access levels below SSACC 
               
               
                 _G.%OCC 
                 Percentage occupancy of unblocked voice channels 
               
               
                 _G.BLK 
                 Number of blocked devices in the cell 
               
               
                 _G.BNC10 
                 10 percentile of non compensated signal strength received by all channels in 
               
               
                   
                 the busy state 
               
               
                 _G.BNC50 
                 50 percentile of non compensated signal strength reccived by all channels in 
               
               
                   
                 the busy state 
               
               
                 _G.BNC90 
                 90 percentile of non compensated signal strength received by all channels in 
               
               
                   
                 the busy state 
               
               
                 _G.BS15 
                 Busy Sat to noise less than 15 dB 
               
               
                 _G.BS20 
                 Busy Sat to noise less than 20 dB 
               
               
                 _G.BS25 
                 Busy Sat to noise less than 25 dB 
               
               
                 _G.BS30 
                 Busy Sat to noise less than 30 dB 
               
               
                 _G.CCAI10 
                 10 percentile average signal strength received by the control channel on 
               
               
                   
                 accesses when the channel was idle 
               
               
                 _G.CCAI50 
                 50 percentile average signal strength received by the control channel on 
               
               
                   
                 accesses when the channel was idle 
               
               
                 _G.CCAI90 
                 90 percentile average signal strength received by the control channel on 
               
               
                   
                 accesses when the channel was idle 
               
               
                 _G.C/I10 
                 % of Carrier to Interference measurements below 10 dB 
               
               
                 _G.C/I15 
                 % of Carrier to Interference measurements below 15 dB 
               
               
                 _G.C/I18 
                 % of Carrier to Interference measurements below 18 dB 
               
               
                 _G.C/I20 
                 % of Carrier to Interference measurements below 20 dB 
               
               
                 _G.C/I25 
                 % of Carrier to Interference measurements below 25 dB 
               
               
                 _G_NACCS 
                 Number of true accesses 
               
               
                 _G.VCI10 
                 10 percentile of non compensated signal strength received by the channels 
               
               
                   
                 when in the idle state 
               
               
                 _G.VCI50 
                 50 percentile of non compensated signal strength received by tbe channels 
               
               
                   
                 when in the idle state 
               
               
                 _G.VCI90 
                 90 percentile of non compensated signal strength received by the channels 
               
               
                   
                 when in the idle state 
               
               
                 CUSTACCF 
                 Customer perceived access failures (%) 
               
               
                 CPROGDO 
                 Call in progress dropouts (%) 
               
               
                 NETCONG 
                 Network congestion (%) 
               
               
                 SERVLOS 
                 Service Loss 
                 (No longer used) 
               
               
                 TOTACC 
                 Total call accesses 
               
               
                 TOTDHO 
                 Total Dropouts incl. handoffs 
               
               
                 TOTDROP 
                 Total Dropouts excl. handoffs 
               
               
                 TRAFOV 
                 Traffic Overflow (%) 
               
               
                 ACCUPR 
                 Accesses due to unknown Page Response 
                 (No longer used) 
               
               
                 DROPHO\U 
                 Dropouts at handoff (%) 
               
               
                 DRSUC 
                 Successful directed retry responses (%) 
               
               
                 INSTXQ 
                 Dropouts due to insufficient TX Quality (%) 
               
               
                 PAGE1 
                 Response to first page 
               
               
                 PAGECON 
                 Page Congestion 
               
               
                 PAGESUC 
                 Successful Pages 
               
               
                 SATFAIL 
                 SAT Failures 
               
               
                 UNCREG 
                 Unconfirmed registrations 
               
               
                 UNSUCHO 
                 Unsuccessful handoffs 
               
               
                 UPRDR 
                 UPR not leading to Directed Retry 
                 (No longer used) 
               
               
                 VCDESDR 
                 VC Designation Failures (dir retry) (%) 
               
               
                 VCDESF 
                 VC Designation Failures (all) (%) 
               
               
                 VCSZE 
                 Voice Channel Seizures 
               
               
                 DO&gt;5 
                 Number of cells DO&gt;5% 
               
               
                 R&lt;SSREG 
                 Registration attempts &lt; SSREG 
               
               
                 ACCALL 
                 All accesses including &lt; SSACC 
               
               
                 A&lt;SSACC 
                 Accesses &lt; SSACC 
               
               
                 ACCMULT 
                 Multiple accesses 
               
               
                 VCSZUHO 
                 Unsuccessful VC seizures at HO 
               
               
                 VCSZCI 
                 VC seizures rejected - low C/I 
               
               
                 _G.BS10 
                 total SAT to noise performance in percentage at the 10 dB level 
               
               
                 _G.BS15 
                 total SAT to noise performance in percentage at the 15 dB level 
               
               
                 _G.BS20 
                 total SAT to noise performance in percentage at the 20 dB level 
               
               
                 _G.BS25 
                 total SAT to noise performance in percentage at the 25 dB level 
               
               
                 _G.BS30 
                 total SAT to noise performance in percentage at the 30 dB level 
               
               
                 _G.CI10 
                 total Carrier to Interference performance percentage for 10 dB 
               
               
                 _G.CI15 
                 total Carrier to Interference performance percentage for 15 dB 
               
               
                 _G.CI18 
                 total Carrier to Interference performance percentage for 18 dB 
               
               
                 _G.CI20 
                 total Carrier to Interference performance percentage for 20 dB 
               
               
                 _G.CI25 
                 total Carrier to Interference performance percentage for 25 dB 
               
               
                 _G.RSS10 
                 10 signal strength percentiles for all of the channels in all of the channels in all 
               
               
                   
                 of the cells under consideration 
               
               
                 _G.RSS50 
                 50 signal strength percentiles for all of the channels in all of the channels in all 
               
               
                   
                 of the cells under consideration 
               
               
                 _G.RSS90 
                 90 signal strength percentiles for all of the channels in all of the channels in all 
               
               
                   
                 of the cells under consideration 
               
               
                   
               
             
          
         
       
     
     Modifications and variations maybe made to the disclosed embodiments without departing from the subject and spirit of the invention as defined by the following claims.