The subject matter described herein relates to the monitoring of wireless bypass traffic events occurring in a communications network. More particularly, the subject matter described herein relates to methods, systems, and computer program products for detecting wireless bypass in a communications network.
Wireless bypass refers to the use of a subscriber identity module (SIM) box or other equivalent device to make calls that originate or terminate with out of network subscribers appear as in-network calls for preferential billing. Wireless service providers often provide preferential billing for mobile calls that originate and terminate between their subscribers. SIM boxes are devices that appear to a wireless network as multiple handsets. They have authorized uses, such as terminating calls between different corporate sites.
SIM boxes also have unauthorized uses. One unauthorized use of a SIM box is wireless bypass. In one wireless bypass scenario, a wireless bypass provider may market international calling at a discounted rate over rates provided by network operators. The wireless bypass provider may provide an access number for customers to access the discount international calling service. The customer dials the access number and enters the called party number. The call may be routed over a voice over Internet Protocol (VoIP) network through a SIM box in the called party's network to make the call appear as an in-network call. The call will thus receive a preferred rate. The SIM card used in a SIM box may be prepaid SIM cards because they can be anonymously purchased and recharged.
One problem with this and other wireless bypass scenarios is that wireless bypass calls utilize network resources that would be available for legitimate calls. If the volume of wireless bypass calls is large, legitimate calls can be precluded or can receive degraded service.
Accordingly, there exists a need for methods, systems, and computer program products for detecting wireless bypass in a wireless communications network.
The subject matter described herein includes methods, systems, and computer program products for detecting wireless bypass in a communications network. One method includes analyzing at least one of wireless signaling message traffic in a wireless communications network, financial information regarding wireless communications network subscriptions, and subscriber records maintained in the wireless communications network. The method also includes determining, based on the analysis, whether a wireless bypass signature is indicated. In response to determining that a wireless bypass signature is indicated, a mitigating action is performed.
The subject matter described herein for detecting wireless bypass may be implemented using a computer program product comprising computer executable instructions embodied in a tangible computer readable medium that are executed by a computer processor. Exemplary computer readable media suitable for implementing the subject matter described herein includes disk memory devices, programmable logic devices, and application specific integrated circuits. In one implementation, the computer readable medium may include a memory accessible by a processor. The memory may include instructions executable by the processor for implementing any of the methods for detecting wireless bypass described herein. In addition, a computer readable medium that implements the subject matter described herein may be distributed across multiple physical devices and/or computing platforms.
Preferred embodiments of the subject matter described herein will now be explained with reference to the accompanying drawings of which:
The present subject matter relates to systems, methods, and computer program products for detecting wireless bypass in a wireless communications network. In order to better understand the present subject matter, an explanation regarding the manner in which a wireless communications network may be exploited by wireless bypass will now be provided.
An exemplary wireless bypass event may begin at a wireline phone 102 initiating a call which is redirected to SIM box 112, which is operated by a reseller of long distance call services. Notably, SIM box 112 has a subscription (e.g., is provisioned with at least one SIM card that includes a prepaid subscription) to the same wireless network as the called party, e.g., mobile device 104. In one example, the call is routed as a voice-over-IP (VoIP) call over Internet network 108 and is terminated at a private branch exchange (PBX) 110, which is communicatively coupled to SIM box 112.
As described above, SIM box 112 may be programmed with multiple SIM cards and may include multiple antennas. In one embodiment, SIM box 112 is able to support GSM, GPRS, UMTS, and CDMA technologies and may interface with T1/E1, ISDN, and VoIP facilities. SIM box 112 is typically placed in proximity to a base transmission station (BTS), such as BTS 114, which is capable of communicating with the BTSs in network 101. Although SIM box 112 supports multiple SIM card subscriptions, wireless network 101 still recognizes SIM box 112 as a single device since SIM box 112 is assigned a single programmable international mobile equipment identity (IMEI), which is a unique number that designates SIM box 112 as a valid device in a GSM wireless network. In one embodiment, a reseller provisions SIM box 112 with a plurality of prepaid subscription SIM cards. Each SIM card is considered a subscription to the wireless network to which the SIM card is associated.
SIM box 112 is able to initiate and terminate mobile-to-mobile calls with any mobile device using one or more prepaid SIM cards that provides a subscription to network 101. Thus, SIM box 112 is capable of establishing calls in the same manner as any other mobile device belonging to a network. A reseller may use prepaid SIM cards since a prepaid subscription to a network may be registered anonymously and thereby reduce the chances the reseller may be identified. Specifically, using prepaid SIM cards enables a reseller to conceal his identity as opposed to registering a conventional subscription with the wireless service provider (e.g., the service provider of wireless network 101). Because of the high volume of calls typically serviced by the reseller, the prepaid SIM cards are typically “recharged” (i.e., re-provisioned with funds) several times a day as the subscription account becomes depleted. Furthermore, the prepaid cards are usually recharged with high balances in order to handle the number of calls serviced by the reseller. The prepaid SIM cards may also be recharged either in person with cash (thereby assuring anonymity) or over the Internet in a remote manner.
Returning to the discussion of a call originated by calling party 102, the call may initially be routed to IVR 130 via softswitch 110. IVR 130 collects the digits for called party 104. SIM box 112 uses the MSISDN provisioned for one of its subscriptions to re-originate the call as an in-network call to mobile device 104 over BTSs 114 and 116. From BTS 116, the call is ultimately routed to the called party's mobile device 104. By re-originating the call in this manner, a reseller provides a service that allows a subscriber to avoid long distance charges and out-of-network charges since SIM box 112 (i.e., at least one SIM card used by SIM box 112) is making calls as an in-network subscriber.
Although only one wireless network (i.e., network 101) is shown in
A reseller typically arranges for a SIM box 112 to be placed near a BTS tower for optimal communication and to avoid any difficulties and charges associated with roaming. In some instances, the reseller's SIM box may be detected by a network operator due to its stationary nature. To avoid this problem, a reseller may use several SIM boxes, each of which is located near a different BTS. In one instance, as shown in
In order to detect wireless bypass events, the present subject matter may include a wireless bypass detection system (WBDS) 150.
In one embodiment, probe 152 transparently copies the traversing signaling messages and forwards the copied messages to WBDS 150. In an alternate embodiment, WBDS 150 may be implemented as a component module within a network signaling node (as shown below in
In an alternate embodiment, bypass traffic event screening and mitigation module 512 may be implemented as a WBDS screening module 156 within STP 154 as shown in
When a signaling message is received by STP 154, the message may be processed by LIM 610, DCM 606, or HSL 608 depending on whether the message is sent over an SS7 link, an IP signaling link, or a high speed link. The message is passed up the communications protocol stack on the receiving communication module until it reaches the module's respective message distribution function, which forwards the call signaling message to DSM 622. In one embodiment, at least one DSM module 622 in STP 154 is equipped with a WBDS screening module. In one embodiment, WBDS screening module 156 functions in a similar manner to the screening and mitigation module 522 depicted and described in
After collecting signaling data from wireless network 101, WBDS 150 is adapted to analyze the data by inspecting for specific parameters, such as bypass traffic signatures. In one embodiment, WBDS 150 is configured to monitor the collected signaling data for a number of signatures that may indicate a bypass traffic event. In one embodiment, WBDS 150 may employ one or more filters to screen the signaling message traffic to identify the bypass traffic signatures.
In one embodiment, a filter may be designed to recognize one or more wireless bypass signatures. For example, a filter may be used to determine if a subscription (e.g., a prepaid SIM card subscription) fails to roam. Notably, a subscription that does not roam may indicate that a SIM box is servicing bypass traffic. Similarly, a filter may be configured to detect a signature involving a subscription that appears to roam within the network but does so in a semi-fixed pattern. The semi-fixed pattern may include a calling pattern that appears to originate from the same cell sites all the time with little or no deviation.
Another wireless bypass signature that may be monitored for WBDS 150 includes a subscription that always initiates calls but rarely (or never) receives them. SIM boxes are primarily used for making calls as opposed to receiving calls. In one embodiment, a filter may be used to detect a subscription that exhibits a very high call volume (e.g., above normal for most prepaid subscriptions). A high call volume from a given prepaid subscription may indicate a SIM box is being used. Another wireless bypass signature that may be detected by a filter includes a subscription that utilizes an IMEI known to be a SIM box or a GSM gateway that includes a SIM box. Yet another detectable wireless bypass signature may include a subscription that has a high call density. For example, a subscription that originates a call as soon as it releases a previous call may indicate the existence of a bypass traffic event. This may indicate a bypass traffic SIM box that services a call immediately after the previously serviced call releases.
Another wireless bypass signature that may be monitored via a filter includes a subscription that terminates calls to an extremely diverse group of seemingly unrelated mobile devices. Most subscribers have a common group of mobile numbers that are frequently called, such as mobile numbers belonging to friends and family members. However, a subscription related to a SIM box servicing bypass traffic is abnormal in this regard since it is servicing calls to an extremely diverse range of numbers (because a diverse group of callers are being serviced by the SIM box).
Another wireless bypass signature that may be monitored includes subscriptions characterized by calls with durations that are typically longer than normal. A wireless bypass call normally has a longer duration because a subscriber is typically more apt to talk for a longer period of time since the call is charged at a reduced rate. Yet another call bypass signature that may be monitored includes a subscription that does not activate other features or services such as voicemail or data services. Whereas most subscriber use various communication features, a subscription using a SIM box to service bypass traffic exclusively uses voice services since a reseller is only concerned with re-originating calls to wireless network 101.
If a predefined number of these exemplary signatures (or other signature types) are detected by the WBDS filters, then WBDS 150 may access and analyze other sources of information to confirm the bypass nature of the signaling data. In one embodiment, WBDS 150 obtains IMEI and/or MSISDN numbers from the bypass traffic during the filtering process or from collected call detail records (CDRs). Bypass traffic screening and mitigation module 622 may then use certain identification numbers, such as the IMEI number or MSISDN, which are associated with a suspected SIM box from the bypass signaling data to obtain certain financial and subscription data from databases 170 and 180 to verify that the suspected traffic is bypass traffic. In one embodiment, subscriber database 170 contains account information that includes a subscriber identification number, the type of calling device used, as well as other subscriber information. Financial database 180 may include a subscriber identification number, the type of subscription (e.g., prepaid or conventional), payment information, and the like. In one embodiment, WBDS 150 identifies an IMEI number, a TMSI (temporary mobile subscriber identity) number, a MSISDN (mobile subscriber ISDN) number, and an IMSI (international mobile subscriber identity) number from the signaling stream. Collectively, this information may be used to identify the type of device and subscription being used to access wireless network 101. For example, the TMSI/IMSI/MSISDN combination obtained from the collected data may be used to determine whether in-network access is being achieved through a prepaid-type subscription by cross-referencing subscription entries in subscriber database 170. In addition, data analysis module 514 may analyze the collected data to determine if a SIM box is being used to access the network by cross-referencing a suspected identification number (e.g., an IMEI number) with subscriber database 170.
WBDS 150 may also be configured to acquire financial information regarding wireless communications from financial database 180 in order to confirm a suspected source of bypass traffic. After obtaining information from the collected data, bypass traffic screening and mitigating module 522 may cross-reference subscription entries of financial database 180 with a suspected MSISDN or SIM number. For example, if an MSISDN or SIM subscription is associated with a prepaid account that is recharged with exceptionally high amounts, WBDS 150 may flag the MSISDN or SIM number as a wireless bypass service number. In one embodiment, this information may be obtained from event records associated with an IMEI or MSISDN from financial database 180. In addition, WBDS 150 may also be adapted to consider the frequency in which the prepaid subscriptions are recharged. Both signatures may be measured objectively by configuring a filter with predefined threshold (which may be adjusted by a network operator or NOC 120). In an alternate embodiment, databases 170 and 180 may be used by WBDS 150 as a means to detect a bypass event as opposed to being used for confirmation.
In block 704, the call signaling messages are analyzed. In one embodiment, WBDS 150 utilizes a screening and mitigation module 522 to apply filters to the received call signaling messages. Specifically, screening and mitigation module 522 uses the filters in an attempt to detect various call signatures in the wireless signaling message traffic. Similarly, data analysis module 514 may also analyze financial information regarding wireless subscriptions and subscriber records from financial database 180 and subscriber database 170, respectively.
In block 706, a determination is made, based on the analysis, as to whether a bypass traffic event is detected. In one embodiment, data analysis module 514 analyzes the filter results to determine if a possible bypass traffic event exists. For example, if a predefined number of filter thresholds are exceeded, then a possible bypass traffic event is detected. If a possible bypass traffic event exists, then method 700 continues to block 708. If a bypass traffic event is not suspected, then method 700 loops back to block 702 to continue monitoring.
In block 708, a mitigating action is performed. In response to detecting a bypass traffic event, WBDS 150 may perform a mitigation action. In one embodiment, WBDS 150 is configured to alert a network operator of the bypass traffic event. For example, WBDS 150 may send an alarm message to NOC 120. The method 700 then ends.
As mentioned above, WBDS 150 may be configured to perform a mitigating action such as generating an alarm. For example, when a bypass traffic event occurs and is detected by WBDS 150 (or WBDS screening module 156), a network operator may receive an alarm at NOC 120 indicating the bypass traffic event is occurring. Upon receiving the alarm, the operator may analyze the filtered data to confirm the occurrence of the detected bypass traffic. The alarm may also identify the point of origination of the bypass traffic so that other mitigating actions may be performed.
In one embodiment, WBDS 150 monitors mobile originated outbound calls (either as a stand-alone network component or via WBDS screening module 156) and the associated called party digit information (collected via the network operated IVR 158). After sufficient information is gathered to identify the SIM numbers or MSISDNs suspected of being used for the wireless bypass traffic event, WBDS 150 may alarm NOC 120 or may intercept calls directed to the identified offending SIM numbers or MSISDNs. For example,
Upon receiving IAM 402, IVR 158 prompts the caller to enter the desired called party number (i.e., not unlike the manner in which normal prepaid calling card calls are initiated). The calling party, who is likely to be unaware that they are not in communication with an IVR associated with the bypass traffic service or SIM box 112, is likely to comply and enter the requested called party digit information. If the called party digit information corresponds to a number that differs from the originally dialed number (e.g., a number that differs from the SIM device number) a mitigating action may be performed. For example, the call may either be blocked (e.g., dropping the IAM or issuing a release message) or routed to the called party at out-of-network rates. The call may also be forwarded to NOC 120 for other mitigating actions.
In another embodiment, a ping call confirmation system may be utilized in conjunction with WBDS 150. For example,
It will be understood that various details of the subject matter described herein may be changed without departing from the scope of the subject matter described herein. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation, as the subject matter described herein is defined by the claims as set forth hereinafter.
The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/967,808, filed Sep. 7, 2007, incorporated herein by reference in its entirety.
Number | Date | Country | |
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60967808 | Sep 2007 | US |