Abstract:
In the method for monitoring communication in a wireless communication network, a network explorer may be passively attached to the wireless communication network. The network explorer may store data associated with received communication over the wireless communication network and performs an analysis on the stored data. In the apparatus of the network explorer may passively monitor communication over a wireless communication network, store data associated with the communication, and perform an analysis on the stored data.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to wireless communication networks, and more particularly to monitoring and analyzing communication over the network. 
     2. Description of the Related Art 
     For the foreseeable future, two very important market forces may continue in wireless communication networks: the increasing complexity of wireless network services, and the increasing customer demands and competitive pressures upon wireless service providers. Viewed from the perspective of the wireless service provider, these technical and economic trends are a potent combination. 
     The continued growth in network load and the addition of high-speed data services combine to make the network ever more difficult to monitor, trouble-shoot, and optimize using traditional tools alone. It is important to recognize that with the addition of wireless data services, the cell loading behavior has changed in statistically significant ways. Voice users are large in number and their per-mobile communication patterns are comparatively “smooth”. Hence in a statistical sense, aggregate voice loading inherently is more self-averaging within a given cell. However data communication is much more “bursty” and the number of simultaneously served high-speed data users within a cell may be significantly smaller than for voice services. Hence fluctuations in data loading and performance are broader in character than for voice services. Additionally, data&#39;s different statistical characteristics and QOS (Quality of Service) requirements require entirely new network elements, with more complex signaling and control mechanisms throughout. Generally, these trends are apply to generic 3G wireless standards, and may be applied to any existing standard and/or future standard (i.e., these trends are not limited to CDMA2000). 
     The industry&#39;s challenging economic realities require service providers to continually seek avenues for shortening their time to revenue while simultaneously improving their provisioning and optimization abilities to extract the most network performance possible in order to prosper in an increasingly competitive marketplace. The collision of these technical and economic forces presents a clear challenge: to find mechanisms to achieve these economic efficiencies in the face of the growing network complexity. 
     Such methodologies tend to rely heavily on data regarding the performance of the network. Several network monitoring and performance monitoring techniques exist. 
     Traditional network Service Measurements (SMs) are typically averaged or accumulated over some measurement period, e.g., one hour. Such SMs are well suited to performance monitoring situations where the relevant quantity is deterministic and readily measurable, often associated with a particular network sub-element. An example might be the peak number of Walsh codes in use during the hour. As long as this peak demand does not exceed the maximum number of available codes, one can safely conclude that no performance degradation directly resulted. However, there also exist situations, which require comparisons or correlations between multiple quantities at a specific time within the measurement period, and these often require the SMs to be binned upon much finer time scales in order to draw statistically valid conclusions. Namely, there exist situations which require much more detailed knowledge regarding the full network state as a function of time. Two examples might be understanding and managing the interactions between simultaneous voice and data users on the same carrier, and gaining a deeper understanding regarding the confluence of events which can lead to lost calls. 
     Per-call service measurements are an important step along the path towards more detailed information on finer time scales, but they too have their limitations. Typically they retain only a subset of the system state and performance metrics, to avoid presenting an undue burden upon the network infrastructure. 
     Drive testing has long been an important tool for performance monitoring and diagnosis, and likely will continue for many years. However, there exist numerous situations where the actual user behavior is critical to understanding the network behavior and performance, something drive testing can at best only approximate. For example, data performance and provisioning are keenly dependent upon accurate packet data communication models, data user locations within the cell, the number and activity of simultaneous users, their mobility, etc. Drive testing is also relatively expensive, so collecting detailed performance data from actual user mobiles provides an important opportunity for cost reduction. 
     SUMMARY OF THE INVENTION 
     In the wireless network explorer of the present invention, communication on a wireless network may be passively monitored and analyzed such that no load is added to the wireless network. The wireless network explorer may include a plurality of state machines for responding to given elements within the received communication. Call characteristics associated with the received communication may be stored in a database for later analysis. 
     In one embodiment, the aggregate information compiled in the database may be analyzed to perform mobile location and propagation loss analysis on received communication. In another embodiment, a temporal analysis may be performed on various stored call characteristics within the database. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, wherein like reference numerals designate corresponding parts in the various drawings, and wherein: 
         FIG. 1  illustrates the network architecture of a wireless network according to an exemplary embodiment of the present invention. 
         FIG. 2  illustrates a block diagram of the wireless network explorer for monitoring and analyzing communication on a wireless network according to an exemplary embodiment of the present invention. 
         FIG. 3  illustrates one exemplary embodiment of a state machine unit. 
         FIG. 4  illustrates an example of data queried and organized by the feature extractor of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates the network architecture of a wireless network  50  according to an exemplary embodiment of the present invention. As shown, mobile stations (MS)  10  (e.g., cell phones, wireless equipped laptops, PDAs, etc.) may communicate with respective base stations (BS)  15  in both an uplink (i.e., to the base station) and a downlink (i.e., from the base station) direction. The BSs  15  may also communicate with their respective mobile switch center (MSC)  25  over a backhaul. In wireless network technology, the backhaul is a connection to transmit voice and data traffic between a remote-sited transmitter/receiver (e.g., BS) and its destination (e.g., a central site such as a MSC). The communication may include at least one of a voice communication and/or a data communication. In the case of voice, the MSC  25  may connect voice calls with other MSCs or with a wireline network such as the public telephone switch network (PTSN). In the case of data, the MSC  25  may provide the connection to the inter-working function (IWF) (or packet control function (PCF) and packet data server node (PDSN)), after which the packets are routed to an the appropriate destination. Apart from switching, the MSC  25  provides diagnostic information and billing statistics. 
     In an exemplary embodiment of the present invention, a wireless network explorer  30  may monitor the link between at least one BS  15  and the MSC  25 . The wireless network explorer  30  may be connected to the MSC  25  as illustrated in  FIG. 1 . The wireless network explorer  30  may receive input from the MSC  25  via an access point of the backhaul of the MSC  25 . The connection of the wireless network explorer  30  to the MSC  25  via the backhaul is passive and does not affect and/or interfere with the performance of the wireless network  50 . 
     The wireless network explorer  30  may be configured to monitor the carriers of at least one of the BSs  15 . For example, two BSs  15  may reside within a geographical range of interest to a system analyst. In this example, it may be preferable to analyze each of the two BSs  15  within the geographical range of interest. Alternatively, the system designer may focus on a single BS  15 . 
       FIG. 2  illustrates a block diagram of the wireless network explorer  30  for monitoring and analyzing communication on the wireless network  50  according to an exemplary embodiment of the present invention. The wireless network explorer  30  may include link transceivers  200  (e.g. T 1 /E 1  transceivers) to parse data from the voice/data packets transmitted on the backhaul between the MSC  25  and one or more BSs  15 . 
     In another exemplary embodiment of the present invention, the wireless network explorer  30  may include a processor board connected to a chassis of the MSC  25 , thereby enabling a capture of messaging between the MSC  25  and the BSs  15 . In this embodiment, software for the wireless network explorer  30  may be executed on the processor board. 
     The wireless network explorer  30  may include a protocol decoder  210  for parsing the different types of messages received from the link transceivers  200 . These messages may include, but are not limited to, control messages between the MSC  25  and the BS  15 , traffic frames between the MSC  25  and the BS  15 , soft hand-off messages relayed between BSs  15 , reverse link mobile signaling messages, forward link mobile signaling messages, aggregated BS  15  loading reports, etc. 
     The wireless network explorer  30  may include a state machine unit  220 , the state machine unit  220  runs a state machine for each monitored call based on the data parsed by the protocol decoder  210 .  FIG. 3  illustrates one exemplary embodiment of a state machine unit  220 . 
     A state machine is created for a call when either a call origination message is received or a secondary handoff request is received. If the state machine unit  220  determines that a call origination message is received, the state machine unit  220  transitions the state machine from a first initial state Init 1  to a first waiting state Wait 1 . If the state machine unit  220  determines that a secondary handoff request is received, the state machine unit  220  transitions the state machine from the first initial state Init 1  to a second waiting state Wait 2 . 
     Call Origination Message 
     An exemplary embodiment of the present invention will now be described wherein the state machine unit  220  receives a call origination (e.g., from a mobile station or a network) message while in the first initial state Init 1 . As described above, the state machine unit  220  transitions the state machine to the first waiting state Wait 1  upon receipt of the call origination message. In the first waiting state Wait 1 , the state machine unit  220  records the elements listed below in Table 1 with respect to the call. 
     In another exemplary embodiment of the present invention, whenever the state machine unit  220  records any element associated with the call, the location of the mobile station, which is within the analyzed wireless communication, and a time stamp associated with the call characteristic being stored (e.g., in the case of a call origination message, the time at which the mobile station began the call would be recorded in the time stamp) are also recorded with the associated element. 
     
       
         
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Element 
                 Examples 
               
               
                   
               
             
             
               
                 Parameters 
                 ESN/ID of the mobile station 
               
               
                 associated with the 
                 Cell site 
               
               
                 received message 
                 Carrier handling the call 
               
               
                 and the mobile 
                 Sector handling the call 
               
               
                 station from which 
                 Signature of the hardware element that is handling 
               
               
                 the message was 
                 the call 
               
               
                 received. 
                 A requested service option 
               
               
                   
                 i. Voice 
               
               
                   
                 ii. Data 
               
               
                   
                 iii. Facsimile 
               
               
                   
                 The radio configuration (RC) 
               
               
                   
                 i. RC-1 
               
               
                   
                 ii. RC-2 
               
               
                   
                 iii. RC-3 
               
               
                   
                 iv. RC-4 
               
               
                   
                 v. RC-5 
               
               
                   
                 The incoming state of the mobile station 
               
               
                   
                 i. Fast moving 
               
               
                   
                 ii. Slow moving 
               
               
                   
               
             
          
         
       
     
     The first waiting state Wait 1  transitions to a call failure state CallFail 1  when a call processing/release failure message is received, and the state machine unit  220  records the elements listed below in Table 2 with respect to the call. 
     
       
         
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Element 
                 Description 
                 Examples 
               
               
                   
               
             
             
               
                 Call blocks and 
                 Information that indicates the 
                 Cell hardware 
               
               
                 associated 
                 call origination attempts are 
                 Radio link 
               
               
                 information 
                 blocked due to resource 
                 MSC hardware 
               
               
                   
                 limitations 
                 Backhaul 
               
               
                   
                   
                 Walsh code 
               
               
                 Ineffective call 
                 Information that indicates that 
                 Acquiring a mobile 
               
               
                 attempts and 
                 call attempts become ineffective 
                 in a traffic channel 
               
               
                 associated 
                 due to various reasons 
                 Service option 
               
               
                 information 
                   
                 connection 
               
               
                 Data Specific 
                 Information that indicates a QOS 
                 Denied data 
               
               
                 Quality of Service 
                 problem. 
                 channel 
               
               
                 (QOS) problem. 
                   
                 Burst delay 
               
               
                   
               
             
          
         
       
     
     Alternatively, the first waiting state Wait 1  transitions to a primary simplex call state PrimarySimplex 1  when a traffic channel confirmation message is received. In the primary simplex call state PrimarySimplex 1 , the base station that is being monitored is the primary base station for the call and has the only leg that is handling the call (i.e., the call is not in soft handoff). 
     In the primary simplex call state PrimarySimplex 1 , if a call release message is received, the state machine unit  220  transitions the state machine to an end of normal call state EndOfNormalCall 1 . Alternatively, the state machine unit  220  transitions the state machine to the call failure state CallFail 1  when a call processing/release failure message is received. 
     Further, in the primary simplex call state PrimarySimplex 1 , if a handoff direction message is received (i.e., a message indicating that the call is in a soft handoff with at least 2 sectors), the primary simplex call state PrimarySimplex 1  transitions to a primary N-way call state PrimaryNWay 1 . 
     The state machine remains in the primary N-way call state PrimaryNWay 1  until one of a call release message, a call setup failure message, and a handoff removal message resulting in only one leg (i.e., one BS) handling a call (e.g., a handoff removal message indicating that the call is still in soft handoff with at least two legs would not qualify) is received. When the call release message is received, the state machine transitions to the end of normal call state EndOfNormalCall 1 . When the call setup failure message is received, the state machine transitions to the call failure state CallFail 1 . When the handoff removal message resulting in only one leg handling the call is received, the state machine transitions back to the primary simplex call state PrimarySimplex 1 . When a handoff removal message is received which results in at least two legs handling the call is received, the state machine remains in the primary N-way call state PrimaryNWay 1 . 
     In the states PrimarySimplex 1  and/or PrimaryNWay 1 , the state machine unit  220  records the elements listed below in Table 3 for the call. 
     
       
         
               
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 Element 
                 Description 
                 Examples 
               
               
                   
               
             
             
               
                 Handoff triggers 
                 Handoff triggers are messages sent by the 
                 pilot PN 
               
               
                   
                 mobile when the strength of the pilots in the 
                 strength and arrival time of 
               
               
                   
                 active, candidate and neighbor sets exceed or 
                 the active set 
               
               
                   
                 drop below a given static or dynamic 
                 strength and arrival time of 
               
               
                   
                 threshold. In response to the handoff triggers, 
                 the candidate set 
               
               
                   
                 the core network may instruct the mobile to 
                 the round trip time of the 
               
               
                   
                 add a pilot, drop a pilot, or take no action. 
                 message 
               
               
                   
                 Effective management of handoff triggers may 
                 Eb/No and Ec/Io loss metric 
               
               
                   
                 reduce a number of call drops and/or 
                 at the primary leg 
               
               
                   
                 increase network capacity. 
                   
               
               
                 Active set 
                   
                 the pilot PN handling the call 
               
               
                   
                   
                 the leg add time 
               
               
                   
                   
                 type of handoff (e.g., soft or 
               
               
                   
                   
                 softer) 
               
               
                 Trace of handoff 
                 all pilots that were handling the call 
                 leg remove time 
               
               
                 legs 
                 throughout the span of the call 
                 leg add time 
               
               
                 Forward 
                 The gain values of control signals sent by the 
                 gain values 
               
               
                 transmitted gain in 
                 primary leg to the secondary legs. The gain 
                   
               
               
                 radio configuration 
                 values may be interpolated using the base 
                   
               
               
                 (RC) 1-calls 
                 station forward power control algorithm 
                   
               
               
                 voice traffic type 
                 Frame rate and whether erasure or not. 
                 full 
               
               
                   
                   
                 half 
               
               
                   
                   
                 quarter 
               
               
                   
                   
                 eighth 
               
               
                 Reverse frame 
                 The frame erasure rate (FER) on the reverse 
                 Average RFER 
               
               
                 erasure rate (RFER) 
                 direction is based on the “selected reverse 
                 Instantaneous RFER 
               
               
                   
                 traffic type” as sent on the forward direction. 
                   
               
               
                 Selected leg in each 
                 The frame selector is located at the MSC and 
                 Leg identifier 
               
               
                 frame in the reverse 
                 in every forward frame, the MSC sends the 
                   
               
               
                 direction 
                 selected leg information to all the legs 
                   
               
               
                   
                 handling the call. 
                   
               
               
                 Forward frame 
                 The forward frame erasure report calculation 
                 See PSMM below 
               
               
                 erasure report 
                 is based on the power measurement report 
                   
               
               
                   
                 (PMRM) message from the mobile for calls in 
                   
               
               
                   
                 soft handoff. 
                   
               
               
                 Pilot strength 
                 The mobile sends PSMM to the base station 
                 Signal strength 
               
               
                 measurement 
                 based on active and candidate set pilot 
                 Arrive time 
               
               
                 message (PSMM) 
                 activity as well as periodically if ordered by 
                   
               
               
                   
                 the primary cell. 
                   
               
               
                 Layer-3 forward 
                 All types of mobile signaling messages may be 
                 General/Universal Handoff 
               
               
                 mobile signaling 
                 recorded for analysis 
                 Direction message 
               
               
                 messages 
                   
                 (GHDM/UHDM) 
               
               
                   
                   
                 Extended supplemental 
               
               
                   
                   
                 channel assignment message 
               
               
                   
                   
                 (ESCAM) 
               
               
                   
                   
                 Neighbor list message 
               
               
                   
                   
                 System parameters message 
               
               
                   
                   
                 Alert with info message 
               
               
                 3Glx forward and 
                 Characteristics of the forward and reverse 
                 Setup time 
               
               
                 reverse 
                 SCH (i.e., the data activity) 
                 Duration 
               
               
                 supplemental 
                   
                 Rate (2x/4x/8x/16x) 
               
               
                 channel (SCH) 
                   
                 Backlog (at MSC for forward 
               
               
                   
                   
                 burst) 
               
               
                   
                   
                 Data burst aborts 
               
               
                   
                   
                 Anchor cell ID (forward burst) 
               
               
                   
                   
                 Anchor Transfer 
               
               
                   
                   
                 Diversity offset 
               
               
                   
                   
                 Characteristics of the data 
               
               
                   
                   
                 call/burst 
               
               
                   
                   
                 i. RLP single/double 
               
               
                   
                   
                 ii. MUX PDU 
               
               
                   
                   
                 iii. QOS class 
               
               
                   
                   
                 iv. QOS level 
               
               
                 SCH denials and 
                 If the SCH is denied by the cell or by the MSC, 
                 Cell hardware limit 
               
               
                 associated 
                 the event is reported along with an 
                 Backhaul limit 
               
               
                 information 
                 approximate reason. 
                 RF limit 
               
               
                   
                   
                 MSC limit 
               
               
                   
                   
                 Walsh code limit 
               
               
                 Radio Link Protocol 
                 RLP is a NAK based layer-2 protocol that is 
                 Round trip time (RTT) at the 
               
               
                 (RLP) level details 
                 used on the radio link for data calls. 
                 RLP layer 
               
               
                   
                   
                 Retransmission percentage 
               
               
                   
                   
                 Reason for retransmission 
               
               
                   
                   
                 Reason for idle timeouts 
               
               
                 Assigning a service 
                 A service option is assigned to a call based on 
                 Voice 
               
               
                 option 
                 a service option request. 
                 Data 
               
               
                   
                   
                 Facsimile 
               
               
                   
               
             
          
         
       
     
     In the call failure state CallFail 1 , the reason or reasons for the call failure are recorded by the state machine unit  220 . The state machine unit  220  outputs the stored information associated with the call to a report generator  240 . The state machine unit  220  transitions the state machine back to the initial state Init 1  after the information is output. This ends the state machine for that call. 
     In the end of normal call state EndOfNormalCal, the state machine unit  220  records the mobility class of the call (i.e., the state of the call when the call ends) and details of the primary transfer (i.e., the base station ID of both the new and old primary BS and the active set before and after primary transfer). The state machine unit  220  outputs the stored information associated with the call to the report generator  240 . The state machine transitions back to the initial state init 1  after the information is recorded and output. This ends the state machine for that call. 
     Secondary Handoff Request 
     An exemplary embodiment of the present invention will now be described wherein the state machine unit  220  receives a secondary handoff request message. As described above, the state machine unit  220  establishes a state machine in the first initial state Init  1  and transitions the state machine to the second waiting state Wait 2  upon receipt of the secondary handoff request. In the second waiting state Wait 2 , the state machine  220  records the elements listed above in Table 1 for the call. 
     The second waiting state Wait 2  transitions to the call failure state CallFail 1  when a call setup failure message is received, and the state machine unit  220  records the elements listed above in Table 2 for the call. The second waiting state Wait 2  transitions to the state EndOfNormalCall 1  when the call release message is received, and the state machine unit  220  records the elements listed above in Table 2 for the call. 
     Alternatively, the second waiting state Wait 2  transitions to a secondary call N-way state SecondaryCallNWay when a secondary handoff acknowledgment message (SHAM) is received. In the secondary call N-way state SecondaryCallNWay, the base station that is being monitored handles the call as a secondary base station; namely, the call is being handled by some other base station as the primary base station. 
     In the state SecondaryCallNWay, the elements above-described in table 3 except for the handoff triggers are recorded. In the state SecondaryCallNway, the state machine transitions to the state PrimaryCallNWay when a primary transfer message is received resulting in more than one leg (i.e., BS) handling the call (i.e., the call enters soft handoff). If the state machine unit  220  receives a secondary call handoff direction message (i.e., a message indicating an addition or removal of sectors) with the call being handled by the same or different primary base station, the state machine remains in the state SecondaryCallNway. When the call release message is received, the state machine transitions to the end of normal call state EndOfNormalCall 1 . When the call setup failure message is received, the state machine transitions to the call failure state CallFail 1 . Alternatively, the state machine transitions to the state PrimarySimplex 1  when the received primary transfer message results in only one leg (i.e., BS) handling the call (i.e., the mobile station is not in soft handoff). 
     The wireless network explorer  30  may include an event based reporting unit  225 . The event based reporting unit  225  may receive and analyze incoming communication from the backhaul and determine whether given events (e.g., call release, anchor transfer, RLP retransmission, 3GX1 data burst setup, etc. . . . ) have occurred in calls within the wireless network  50 . If one of the given events is found at the event based reporting unit  225 , then the one of the given events may be sent to the report generator  240  along with the state of the call. The given events may include the elements listed below in Table 4 for the call. 
     In another exemplary embodiment of the present invention, the state machine unit  220  also records the elements listed below in Table 4 for the call when the state machine is in the SecondaryCallNWay, PrimarySimplex 1  or PrimaryCallNWay states. 
     In another exemplary embodiment of the present invention, the recorded elements stored at the state machine unit  220  during the execution of the state machine are sent to the report generator  240  after the end of a monitored call (i.e., after either of states CallFail 1  and/or EndOfNormalCall 1 ). 
     
       
         
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                 Received message 
                 Reported Information 
               
               
                   
               
             
             
               
                 Handoff Trigger 
                 pilot PN 
               
               
                   
                 strength and arrival time of the active set 
               
               
                   
                 strength and arrival time of the candidate set 
               
               
                   
                 the round trip time of the message 
               
               
                   
                 Eb/No and Ec/Io loss metric at the primary leg 
               
               
                 SCH setup, denial, 
                 Setup time 
               
               
                 abort and 
                 Duration 
               
               
                 release 
                 Rate (2x/4x/8x/16x) 
               
               
                   
                 Backlog (at MSC for forward burst) 
               
               
                   
                 Data burst aborts 
               
               
                   
                 Diversity offset 
               
               
                   
                 Reason for SCH failure 
               
               
                   
                 i. Cell hardware limit 
               
               
                   
                 ii. Backhaul limit 
               
               
                   
                 iii. RF limit 
               
               
                   
                 iv. MSC limit 
               
               
                   
                 v. Walsh code limit 
               
               
                 Anchor setup, release 
                 Anchor cell ID (forward burst) 
               
               
                 and transfer 
                 Anchor transfer and reason 
               
               
                   
                 Whether an active burst was aborted due to a 
               
               
                   
                 transfer 
               
               
                 RLP frames (e.g., 
                 Round trip time (RTT) at the RLP layer 
               
               
                 RLP control 
                 Retransmission percentage 
               
               
                 frames) 
                 Timing of negative ACKs and retransmission 
               
               
                   
                 Timing of idle timeouts 
               
               
                   
               
             
          
         
       
     
     A report generator  240  receives the outputs as described above from the state machine unit  220  and generates event triggered and periodic reports based on the received outputs. Event reporting may be triggered by information received from the state machine unit  220  and/or the event based reporting unit  225 . 
     In addition to events triggering a report in the report generator  240 , periodic reports based on communication conditions in the wireless communication network  50  may be scheduled in the periodic message processor  230 . The periodic reports are based on communication between the MSC  25  and the BS  15  related to resource loading, operation, administration and maintenance. The timers and triggers (i.e., the determination of when the periodic reports are generated) are controlled within the BS  15  and MSC  25  (i.e., the periodic message processor  230  decodes the communication to determine the periodic messages and sends them to the report generator  240  to be reported). Similar to the state machine unit  220 , the periodic message processor  230  may provide parsed data to be formatted as a report from the protocol decoder  210  to the report generator  240 . 
     In an exemplary embodiment of the present invention, the wireless network explorer  30  may store the information generated by the state machine unit  220 , the event based reporting unit  225  and the periodic message processor  230  in an index entry within a database  250 . Any type of class, quantifier, metric, etc. . . . , associated with the call may be stored in the index entry. An example of information stored in the index entry may include, but is not limited to, a unique identifier of a mobile station (e.g., MIN/ESN), a service option of the mobile station (e.g., Rate Set- 1  EVRC Voice, Rate-Set  2  Voice, 3G IP, 3G CDPD, etc. . . . ), an identifier of the BS  15  that supports the mobile station, and/or 3G1x data call configuration settings (e.g., Channel Coder Type (Turbo/Convolution), RLP Type, MUX Type, QOS level, QOS Class, etc. . . . ). Further, the index entry may include any of the elements described above with respect to the state machine unit  220  in any of tables 1, 2, 3 and 4. 
     Further, as described above, the index entry may contain a time stamp (e.g., for a given call characteristic/event stored in the index entry, an associated time stamp is stored, the time of the time stamp being the time associated for the given call characteristic and not the time of recording the index entry). By having call characteristics stored in the index entry with an associated time stamp for the call, temporal correlations between events may be determined. It will be appreciated that it may be possible to prepare a time correlated analysis of a communication system without the requirement of real-time processing. 
     In another exemplary embodiment of the present invention, the communication which the wireless network explorer  30  receives, records and/or analyzes may include existing messages on conventional wireless networks which are required for managing a user call and/or to handle traffic load. 
     In another exemplary embodiment of the present invention, the communication which the wireless network explorer  30  receives, records and/or analyzes may include messages not required by the communications network. In other words, messaging which serves to support an analysis required by the wireless network explorer  30  may be used. For example, additional data (i.e., data not required to handle communication on the wireless network  50 ) may be generated at one or more network elements (e.g., BS, MSC, etc. . . . ). The additional data may be discarded by the receiving network element (i.e., the unnecessary data is not required at the receiving network element, but is rather intended for analysis at the wireless network explorer  30 ). The wireless network explorer  30  may receive the additional data and record and/or analyze the additional data similar to operations described above with respect to existing data communications. 
     The database  250  may store results in index entries based on a per-call basis. For example, the unique identifier (e.g. Electronic Serial Number (ESN)) of a mobile station may act as the primary key and the cell or MSC  25  may act as the secondary key. The primary key is an attribute or a set of attributes that uniquely identifies a specific instance of an entity. The entity may include any element related to the communication network (e.g., a call, a wireless call, a trigger, a BS, an MSC, etc. . . . ). The primary key may be used to identify and/or access its associated entity from within the database  250 . In order to qualify as a primary key for an entity, the attribute must include the following properties:
         1) a non-null value for each instance of the entity   2) the value must be unique for each instance of an entity   3) the value must not change or become null during the life of each entity instance.       

     More than one attribute may be required to uniquely identify an entity. A primary key that is made up of more than one attribute is known as a secondary key or composite key. Secondary key indices are those used to access a database other than the primary key. 
     Based on the stored index entries in database  250 , a feature extractor  260  may determine an aggregation (i.e., accumulation) over many calls based on call characteristics that may include, but are not limited to, cell site, carrier, sector, radio configuration, signature of the hardware element handling the call, service options, hand-off ratio, mobility class and call failure code. For each category of call characteristics, it may be possible to obtain statistics such as an average and/or distribution of parameters including, but not limited to, Frame Error Rate (FER), resource usage such as walsh code usage, transmitted power, mobile location and propagation loss analysis, backhaul bandwidth and BS/MSC hardware/processor usage, forward transmitted gain in Radio-Config- 1 , voice traffic type, selected leg, SCH performance, RLP performance, geo-location, propagation loss and hand-off overhead (i.e., inter-BS messaging delays). 
     A mobile location and propagation loss analysis may be performed based on the accumulated information of the wireless network explorer  30 . Any well-known mobile location and propagation loss algorithm (e.g., such as used conventionally with data acquired from drive testing) may be applied to the accumulated data. In contrast, conventional methods of performing mobile location and propagation loss analysis require drive testing (i.e., a physical presence in the range of a base station, such as in a vehicle with testing equipment). Thus, by enabling mobile location and propagation loss analysis from the wireless network explorer  30 , mobile location and propagation loss analysis becomes faster (i.e., location data may be accessed more quickly through the database  250 ), cheaper (i.e., drive testing requires expensive equipment and many man-hours), and more accurate (i.e., drive testing provides limited amounts of data for mobile location and propagation loss analysis). 
     The feature extractor  260  may also give results on a per-call basis (e.g., results on a single user ID throughout the call span for as long as the user remains within the footprint of the base stations being monitored may be provided). Alternatively, the feature extractor  260  may give results on a per-user basis (i.e., the calls may be sorted by the ID associated with a given mobile), time based (i.e., the results may be sorted by the time the data was recorded), or may be sorted by any other element queried by the feature extractor  260 . The wireless network explorer  30  may be configured to simultaneously monitor a plurality of BSs  15  on a same frequency carrier. Once the index table is created for the calls handled by the BSs  15 , the feature extractor  260  may obtain statistics for those calls whose ESN has spanned multiple BSs  15  (i.e., mobile stations whose calls entered soft handoff). Chronological ordering may enable the trace of the call throughout the region of the monitored BSs to be determined. The wireless network explorer  30  may also be configured to provide different classes of performance metrics (e.g., the performance metrics described above with respect to the state machine unit  220 ) for different BSs  15  that are monitored. 
     The feature extractor  260  may include software which may query the database  250  relating to various stored elements in the index entries. For example, the feature extractor  260  may identify a call failure, determine the traffic type of the call related to the call failure, and extract the hand-off matrix and/or hand-off triggers of the call related to the call failure. 
     The results of the feature extractor  260  may be sent to a peripheral device  265 , for example a network printer and/or a storage device. The results of the feature extractor  260  may also be displayed on a display  270 , for example a computer monitor, for viewing by a user. Further, the wireless network explorer  30  may include a user interface  275 . The user interface  275  allows a user to select features which the feature extractor  260  may extract and analyze. For example, the user interface  275  may allow a user to define the queries used by the feature extractor  260 . The user interface  275  may be a remote computer terminal and/or a local computer terminal. Further, the user interface  275  may be a Graphical User Interface (GUI) or other type of user interface. The results of the feature extractor  260  may also be sent to a remotely located external system  280 . 
     In another exemplary embodiment of the present invention, the above described database  250  may be created and accessed through any well-known database structure. For example, the database  250  may be an object oriented database and well-known object oriented data base techniques such as established by the queries may be used by the feature extractor  260  on the database  250 . 
     An example of call data queried by the feature extractor  260  will now be described in detail. It is understood that the specific data queried is meant for example purposes only, and that additional types of data may also be queried by the feature extractor  260 . 
       FIG. 4  illustrates an example of data queried and organized by the feature extractor  260 . The elements listed as column headers in  FIG. 4  are defined in Table 5 below. The values associated with the elements in  FIG. 4  are given as integers, state names, decimals and/or hexadecimal numbers (e.g., hexadecimal numbers begin with “0×” followed by the number). 
     The elements illustrated in  FIG. 4  and listed below in Table 5 are examples only, and do not represent a complete listing of all possible elements that may be queried by the feature extractor  260 . For example, additional elements may include, but are not limited to, handoff triggers, handoff matrices, call flow states, etc. . . . 
     
       
         
               
               
             
           
               
                 TABLE 5 
               
               
                   
               
               
                 Element 
                 Definition 
               
               
                   
               
             
             
               
                 CallSummary# 
                 Index Number. 
               
               
                 CCU and CE 
                 The CCU and the CE are the signature of the hardware 
               
               
                   
                 element handling the call segment at the BS. The CCU 
               
               
                   
                 and the CE may be displayed in hexadecimal. 
               
               
                 CALLID 
                 This is the Identification Number assigned by the MSC 
               
               
                   
                 to every call segment that the BS handles. It is unique 
               
               
                   
                 for this call segment. The CALLID may be displayed as 
               
               
                   
                 a hexadecimal number. 
               
               
                 IncomingState 
                 The IncomingState indicates whether the call originated 
               
               
                   
                 in this BS (i.e., via NOT_A_HANDOFF), or whether it was 
               
               
                   
                 a soft handoff (i.e., via SOFT_HANDOFF), semi-soft 
               
               
                   
                 handoff (i.e., via SEMI_SOFT_HANDOFF) or hard 
               
               
                   
                 handoff (= HARD_HANDOFF). 
               
               
                 EndingState 
                 The EndingState indicates whether the call ended 
               
               
                   
                 normally in this BS (i.e., via NOT_A_HANDOFF) or was 
               
               
                   
                 primary transferred to some other cell site (i.e., via 
               
               
                   
                 PRIMARY_TRANSFER) or semi-soft hand off (i.e., via 
               
               
                   
                 SEMI_SOFT_HANDOFF) or hard handoff 
               
               
                   
                 (HARD_HANDOFF). 
               
               
                 InitialPath 
                 The InitialPath indicates the sector in which the call was 
               
               
                   
                 initially picked up in this BS. Referring to FIG. 4, “0” 
               
               
                   
                 indicates an Alpha sector, “1” indicates a Beta sector 
               
               
                   
                 and “2” indicates a Gamma sector. 
               
               
                 ESN 
                 The electronic serial number for the mobile. The ESN 
               
               
                   
                 may be given in hexadecimal notation. 
               
               
                 ServiceOptionRequested 
                 A service option requested by the mobile. See Table 6 
               
               
                   
                 below for more details. 
               
               
                 ServiceOptionAssigned 
                 A service option assigned by the mobile. See Table 6 
               
               
                   
                 below for more details. 
               
               
                 FwdRadioCfg 
                 The forward radio configuration (e.g., this indicates 
               
               
                   
                 whether the call is 2G, 3G, etc . . . ). See Table 7 below for 
               
               
                   
                 more details. 
               
               
                 ReleaseReason 
                 The reason the call was released or terminated. See 
               
               
                   
                 Table 8 below for more details. 
               
               
                 CallSegmentStartTime_sec 
                 Time at which the call was picked up by this base 
               
               
                   
                 station. The timestamp is given in seconds from the 
               
               
                   
                 time the logging session was started (i.e., the time stamp 
               
               
                   
                 is relative and not absolute). For e.g, if the log session 
               
               
                   
                 begins at 9:00am and the call started at 9:05 am, the 
               
               
                   
                 CallSegmentStartTime_sec would be 300 seconds (i.e., 5 
               
               
                   
                 minutes). 
               
               
                 CallSegmentEndTime_sec 
                 Time at which the call segment ended its association 
               
               
                   
                 with the monitored base station. The ending state may 
               
               
                   
                 be an end of a normal call. a hand over to another base 
               
               
                   
                 station and/or a call failure. The timestamp is recorded 
               
               
                   
                 in seconds from the start of the logging session (i.e., the 
               
               
                   
                 time stamp is relative and not absolute). 
               
               
                 TotalCallSegmentDuration_sec 
                 This is the result of an expression (i.e., 
               
               
                   
                 CallSegmentEndTime_sec − CallSegmentStartTime_sec). 
               
               
                   
                 (See above elements). 
               
               
                   
               
             
          
         
       
     
     Table 6 defines the service options (i.e., ServiceOptionRequested and/or ServiceOptionAssigned as defined in Table 5 and illustrated in  FIG. 4 ) associated with a given hexadecimal number. 
     
       
         
               
               
               
               
             
           
               
                 TABLE 6 
               
               
                   
               
               
                   
                 Value 
                 Acronym 
                 Description 
               
               
                   
               
             
             
               
                   
                 0x3 
                 EVRC 
                 Enhanced Variable Rate Codec 
               
               
                   
                 0x38 
                 SMV 
                 Selectable Mode Vocoder 
               
               
                   
                 0x6 
                 SMS 
                 Short Message Service 
               
               
                   
                 0xE 
                 13KSMS 
                 Short Message Service - 13K 
               
               
                   
                 0x12 
                 8KOTAPA 
                 Over The Air Provisioning 8K 
               
               
                   
                 0x13 
                 13KOTAPA 
                 Over The Air Provisioning 13K 
               
               
                   
                 0x8000 
                 13KVOICE 
                 Voice - 13K 
               
               
                   
                 0x801E 
                 8KMARKOV 
                 Markov Test Call - 8K 
               
               
                   
                 0x801F 
                 13KMARKOV 
                 Markov Test Call - 13K 
               
               
                   
                 0x11 
                 S13KVOICE 
                 Standard 13K voice service 
               
               
                   
                 0x4 
                 8KCDATA 
                 Async data service (9.6 kbps) 
               
               
                   
                 0x5 
                 8KCFAX 
                 Group 3 Facsimile (9.6 kbps) 
               
               
                   
                 0xc 
                 13KCDATA 
                 Async data service (14.4 kbps) 
               
               
                   
                 0xd 
                 13KCFAX 
                 Group 3 Facsimile (14.4 kbps) 
               
               
                   
                 0x7 
                 9IP 
                 packet data 9.6 IP service 
               
               
                   
                 0x8 
                 9CDPD 
                 packet data 9.6 CDPD service 
               
               
                   
                 0xf 
                 14IP 
                 packet data 14.4 IP service 
               
               
                   
                 0x10 
                 14CDPD 
                 packet data 14.4 CDPD service 
               
               
                   
                 0x14 
                 8KAFAX 
                 Analog Fax Rate Set 1(9.6 kbps) 
               
               
                   
                 0x15 
                 13KAFAX 
                 Analog Fax Rate Set 2(14.4 kbps) 
               
               
                   
                 0x1007 
                 9IP_V1 
                 9.6 IP service, version 1 
               
               
                   
                 0x1008 
                 9CDPD_V1 
                 9.6 CDPD service, version 1 
               
               
                   
                 0x16 
                 2GPKTSO22 
                 IS95B packet data SO22 service 
               
               
                   
                 0x17 
                 2GPKTSO23 
                 IS95B packet data SO23 service 
               
               
                   
                 0x18 
                 2GPKTSO24 
                 IS95B packet data SO24 service 
               
               
                   
                 0x19 
                 2GPKTSO25 
                 IS95B packet data SO25 service 
               
               
                   
                 0x2a 
                 2GPKTSO26 
                 IS95B packet data SO26 service 
               
               
                   
                 0x1b 
                 2GPKTSO27 
                 IS95B packet data SO27 service 
               
               
                   
                 0x1c 
                 2GPKTSO28 
                 IS95B packet data SO28 service 
               
               
                   
                 0x1d 
                 2GPKTSO29 
                 IS95B packet data SO29 service 
               
               
                   
                 0x21 
                 3GIP 
                 packet data 3G-1X IP service 
               
               
                   
                 0x22 
                 3GCDPD 
                 packet data 3G-1X CDPD 
               
               
                   
                   
                   
                 service 
               
               
                   
                 0x23 
                 8KGEO 
                 Rate set 1 for Location Services 
               
               
                   
                 0x24 
                 13KGEO 
                 Rate set 2 for Location Services 
               
               
                   
               
             
          
         
       
     
     Table 7 defines the forward radio configuration associated with a given hexadecimal number as illustrated in  FIG. 4 . 
     
       
         
               
               
             
           
               
                   
               
               
                 FwdRadioCfg 
                 Meaning 
               
               
                   
               
             
             
               
                 1 
                 2G RC for rate set 1 (8K) 
               
               
                 2 
                 2G RC for rate set 2 (13K) 
               
               
                 3 
                 3G RC for rate set 1 (8K) 
               
               
                 4 
                 3G RC for forward rate set 1 
               
               
                   
                 (8K) 3G RC for reverse rate set 
               
               
                   
                 2 (13k) 
               
               
                 5 
                 3G RC for rate set 2 (13K) 
               
               
                   
               
             
          
         
       
     
     Table 8 defines the reason that a call was released or terminated. 
     
       
         
               
               
             
           
               
                   
               
               
                 Value 
                 Release reason (i.e., cause) 
               
               
                   
               
             
             
               
                 0 
                 Normal Release 
               
               
                 1 
                 Loss of MSC&#39;s Speech Handler 
               
               
                   
                 Continuity 
               
               
                 2 
                 Loss of Mobile traffic - LOST 
               
               
                   
                 CALL 
               
               
                 3 
                 Service Option Rejected 
               
               
                   
               
             
          
         
       
     
     The exemplary embodiments of the present invention being thus described, it will be obvious that the same may be varied in many ways. For example, the wireless network explorer  30  may be applied to a 2G, 3G, 3G1X, 3G3X, EVDO, EVDV, UMTS and/or other protocol for a wireless network. The wireless network explorer  30  may summarize typical user behavior, throughput, delay, and timeouts and may quantify general system constraints affecting the performance of the communication network. 
     Further, above-described applications for the wireless network explorer  30  have generally been directed to a CDMA2000 cellular network. However, the wireless network explorer  30  is applicable to any type of wireless network (e.g., cellular, 802.11b, 802,11a, 802.11g, VOIP, Bluetooth, RF, etc. . . . ). Thus, while the term “BS” has been above described to indicate a base station in a wireless network, it is understood that the BS may also indicate a NodeB (e.g., UMTS) and/or other wireless emitters/receivers (e.g., as included in 802.11b, 802,11a, 802.11g, Bluetooth, RF, etc. . . . ) that may be connected to the wireless network. 
     Further, above-described exemplary embodiments describe a monitoring of communications between a BS and an MSC. However, the wireless network explorer  30  may monitor communication at any point within the wireless communications network (e.g., R-P, A bis , A3, A7, SS7, I u , I ub , I ur , G b , G n , G i , etc. . . . ). 
     Further, the above-described state machine unit  220  has been described generally with regard to 3G voice communications. However, the state machine unit  220  may be configured for any type of wireless standard (e.g., 2G, 3G, 3G1X, 3G3X, 4G, EVDO, EVDV, UMTS, etc. . . . ) as well as voice, data, facsimile, etc. . . . 
     Further, link protocols have been above-described as either T 1  or E 1 . However, any link protocol may be used (e.g., IP, VoIP, etc. . . . ). Also, the link transceiver T 1  may be implemented as any type of transceiver (e.g., an Ethernet transceiver, etc. . . . ). 
     Further, above-described embodiments are directed to a centralized network architecture. However, any type of network architecture (e.g., a flat architecture used in a base station router (BSR), etc. . . . ) may be included for monitoring with the wireless network explorer  30 . The BSR may include the functionality of several network elements (e.g., BS, RNC, SGSN, GGSN or PDSN, etc. . . . ) within a collapsed mobile network architecture. The BSR may directly connect to an IP network (e.g., via an edge router, a serial connection, etc. . . . ). Thus, the wireless network explorer may be connected to monitor BSR messaging on the backhaul or on the IP network at any location where communication between the BSR and the IP network may be intercepted. 
     Further, flat architectures are not limited to a BSR. Thus, the wireless network explorer may be applied to any type of network including a flat architecture (e.g., a network not including a BSR). 
     Further, the above-described MSC has been generally described with respect to a 3G-1X protocol. However, the MSC may also include a base station controller (BSC), a radio network controller (RNC), and/or a selection and distribution unit (SDU). 
     Further, mobility metrics (e.g., above-described anchor activity with respect to 3G-X1, etc. . . . ) that directly affect the SCH (i.e., data activity) may be monitored by the wireless network explorer  30 . 
     Such variations are not to be regarded as a departure from the spirit and scope of the exemplary embodiments of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the present invention.