Abstract:
A method is disclosed for providing law enforcement agencies in a telecommunications network with monitoring or retention data related to multiple telecommunication identities owned by single or multiple operators. The method comprises the step of grouping a number of said telecommunication identities in at least one list of telecommunication identities identified by a corresponding at least one list identification element. Advantages: Possibility to provide Multi-List Requests feature, with no major efforts; advanced functionality that allows combining multiple warrants/queries into one request, with a more efficient handling, duplicate monitoring preservation and correlation mechanisms, also in a multi- operator configuration; saving investigators time and effort.

Description:
TECHNICAL FIELD 
       [0001]    The present invention generally relates to systems, software, methods, nodes and more particularly to mechanisms and techniques, to provide Law Enforcement Agencies with monitoring or retention data related to multiple telecommunication identities owned by single or multiple operators. 
       BACKGROUND 
       [0002]    Lawful Interception is used for legally monitoring voice and data communications between parties of interest to LEA. Data Retention is used to store data generated from e.g. public telecommunication and the Internet, which might be requested by Law Enforcement Authorities in the course of investigations concerning said suspected criminals. In governments around the world, various law enforcement agencies may have the right to authorize this interception/retention in their respective jurisdictions. 
         [0003]      FIG. 1  is part of the prior art and discloses an Intercept Mediation and Delivery Unit IMDU, also called Intercept Unit. The IMDU is a solution for monitoring of Interception Related 
         [0004]    Information IRI and Content of Communication CC for the same target. The different parts used for interception are disclosed in current Lawful Interception standards (see 3GPP TS 33.107 and 3GPP TS 33.108—Release 8). A Law Enforcement Monitoring Facility LEMF is connected to three Mediation Functions MF, MF 2  and MF 3  respectively for ADMF, DF 2 , DF 3  i.e. an Administration Function ADMF and two Delivery Functions DF 2  and DF 3 . The Administration Function and the Delivery Functions are each one connected to the LEMF via standardized handover interfaces HI1-HI3, and connected via interfaces X1-X3 to an Intercepting Control Element ICE in a telecommunication system. Together with the delivery functions, the ADMF is used to hide from ICEs that there might be multiple activations by different Law Enforcement Agencies. Messages REQ sent from LEMF to ADMF via HI 1  and from the ADMF to the network via the X1 — 1 interface comprise identities of a target that is to be monitored. The HI 1  interface is thus used to set the interception orders in the operator network. The Delivery Function DF 2  receives Intercept Related Information IRI from the network via the X2 interface. DF2 is used to distribute the IRI to relevant Law Enforcement Agencies LEAs via the HI2 interface. The Delivery Function DF3 receives Content of Communication CC, i.e. speech and data, on X3 from the ICE. Requests are also sent from the ADMF to the Mediation Function MF 2  in the DF 2  on an interface X1 — 2 and to the Mediation Function MF 3  in the DF 3  on an interface X1 — 3. The requests sent on X1 — 3 are used for activation of Content of Communication, and to specify detailed handling options for intercepted CC. In Circuit Switching, DF 3  is responsible for call control signalling and bearer transport for an intercepted product. Intercept Related Information IRI, received by DF 2  is triggered by Events that in Circuit Switching domain are either call related or non-call related. In Packet Switching domain the events are session related or session unrelated. 
         [0005]    For the activation of Intercept Related Information IRI, the message sent from the ADMF to the DF contains the target identity, which can be, for instance, one of the following: the IMSI, MSISDN or IMEI codes commonly associated to a mobile phone subscription. Moreover, the message sent from the ADMF to the DF contains the address for delivery of IRI (i.e. the LEMF address), which subset of information shall be delivered, a DF 2  activation identity, which uniquely identifies the activation for DF 2  and is used for further interrogation or deactivation, respectively. Furthermore, the message sent from the ADMF to the DF also contains the warrant reference number, if required by national option. 
         [0006]    Intercept Related Information IRI events are generated at various moments, particularly when a call is initiated or ended, or for all supplementary services during a call and also for information which is not associated to a call. That is, there are call-related IRI events and non call-related IRI events. In any case, whenever an IRI event occurs which is originated by or directed to a mobile subscriber, the Intercepting Control Element ICE in the network sends the relevant data to the DF 2  for them to be delivered to the LEMF. 
         [0007]    To assure correlation between the independently transmitted Content of Communication CC and Intercept Related Information IRI of an intercepted call, the following parameters are used: Lawful Interception Identifier LIID, Communication Identifier CID and CC Link Identifier CCLID. Law enforcement can provide an alphanumeric string, the Case Identity to identify a particular surveillance. A case identity may be assigned to a Monitored Object through a command. 
         [0008]    While Lawful Interception is a real-time exercise, data from the past is used when Data Retention is practised.  FIG. 2  belongs to the prior art and shows the Handover Interfaces between a Data Retention System DRS (see ETSI TS 102 656 V.1.2.1 and ETSI TS 102 657 V.1.7.1) at a Communication Service Provider CSP, and an Authorized Organization AO. The figure shows an Administrative Function AdmF used to handle and forward requests from/to the AO. A Data Collection Function DCF collects data from network elements NEs. Storage S is used to collect and retain all possible data collected by the data collection function. The generic Handover Interface adopts a two port structure such that administrative request/response information and Retained Data Information are logically separated. The Handover Interface port 1 HI-A transports various kinds of administrative, request and response information from/to the Authorized Organization AO, and more particularly from/to an Issuing Authority IA thereof, and the organization at the CSP which is responsible for Retained Data matters. The HI-A interface may be crossing borders between countries. This possibility is subject to corresponding national law and/or international agreements. The Handover Interface port 2 HI-B transports the retained data information from the CSP, to the Authorized Organization AO, and more specifically to a Receiving Authority RA thereof. The individual retained data parameters have to be sent to the Requesting Authority at least once (if available). The HI-B interface may be crossing borders between countries. This possibility is subject to corresponding national law and/or international agreements. 
         [0009]    An investigation about subjects suspected of criminal activities does not only involve the monitoring of calls and retrieval of data items related to communications of a single target identity, for example a single MSISDN, IMSI, IMEI, IP address, etc. used by the suspected subjects. It is in fact often needed to extend the investigation to multiple identities, for example because the subjects suspected of criminal activities use more than one handset or because the investigation has to consider also other people in relationship with the suspected and whose conversations with each other and with the suspected are also under investigation. This scenario is even more complicated in case the target identities are owned by different operators or providers. 
         [0010]    In order for a LEA to monitor all those target identities, several warrants or requests have to be used in the existing Lawful Intercept and Data Retention systems, one for each identity. Even in rather simple investigations, the Authorities need to manage a number of warrants or requests and a number of target identities, which are likely to be spread among different operators. This management is costly and time consuming for the LEA investigators. Moreover, often the data retrieved and the intercepted calls obtained by a LEA are duplicated, because they relate to cross-communications between e.g. two subjects whose identities are both a target of the same investigation. Much time is wasted to discard the duplicate information retrieved, or to correlate the various information with each other within the same investigation. 
       SUMMARY 
       [0011]    The above-mentioned problem and others are solved by the invention which provides a new functionality for Lawful Intercept and Data Retention that allows combining multiple warrants/queries into one request. In particular, it is described an enhancement of the handover interfaces HI 1 /HI-A of Lawful Interception LI and Data Retention DR, respectively, which allow to trigger a single warrant with multiple targets included in lists for Lawful Intercept, and performing multiple queries towards those lists in Data Retention, allowing LEA investigators to save time and effort. 
         [0012]    According to one aspect of the invention, a number of telecommunication identities of one or more target users are grouped in at least one list of telecommunication identities which is identified by a corresponding identification element, or list identifier. This list identifier can be used as a correlation item in a further enhancement of handover interfaces HI 2 /HI-B of LI and DR, respectively. This can be useful for example to correlate data related to the same investigation. 
         [0013]    According to another aspect of the invention, the information data retrieved from a telecommunications network which relate to the number of identities included in the list of target identities are tagged with a corresponding list identifier before they are delivered to the Authorities requesting the information data. 
         [0014]    According to a further aspect of the invention, if the multiple identities which are under investigation are managed by a plurality of network operators, then the single warrant/query is repartitioned into a plurality of requests each directed to each of the network operators managing one or more of said identities. 
         [0015]    In one aspect of the invention a Lawful Interception embodiment is disclosed. In another one, the invention works within the framework of a Data Retention application. 
         [0016]    The objects of the invention are achieved by methods, arrangements, nodes, systems and articles of manufacture. 
         [0017]    The invention will now be described more in detail with the aid of preferred embodiments in connection with the enclosed drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is part of the prior art and discloses a block schematic illustration of an Intercept Mediation and Delivery Unit attached to an Intercepting Control Element. 
           [0019]      FIG. 2  is part of the prior art and discloses a block schematic illustration of the Handover Interfaces between a Data Retention System at a Communication Service Provider, and an Authorized Organization. 
           [0020]      FIG. 3  discloses a signal sequence diagram representing an example of use of the invention in a Lawful Intercept environment where a list of identities is owned by a single operator. 
           [0021]      FIG. 4  discloses a signal sequence diagram representing an example of use of the invention in a Lawful Intercept environment where a list of identities is owned by multiple operators. 
           [0022]      FIG. 5  shows a signal sequence diagram representing an example of Data Retention in a simplified environment involving only one operator. 
           [0023]      FIG. 6  discloses a signal sequence diagram representing an example of use of the invention to query the Data Retention system in the environment of  FIG. 5 , where a list of identities is owned by a single operator. 
           [0024]      FIG. 7  shows a signal sequence diagram representing an example of Data Retention in a more complex environment, involving multiple operators. 
           [0025]      FIG. 8  discloses a signal sequence diagram representing an example of use of the invention to query the Data Retention system in the environment of  FIG. 7 , where a list of identities is owned by multiple operators. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]      FIG. 3  discloses a signal sequence diagram representing an example of use of the invention in a Lawful Intercept environment where a list of identities is owned by a single operator. An enhancement of the handover interface HI 1  of the Intercept Unit (see  FIG. 1 ) previously discussed is proposed, which allows to trigger a single warrant with multiple identities, belonging to one or more target users included in one or more lists. These lists can be any one of e.g. blacklists (i.e. lists containing identities belonging to known criminals), whitelists (i.e. lists of identities which are clearly not belonging to suspected subjects), and greylists (i.e. lists of identities belonging to suspected subjects). These lists are identified by a list identifier List_id which is also used as a correlation item, thus enhancing the interface HI2 of the Intercept Unit. 
         [0027]    In the first example of  FIG. 3 , the multiple identities of one or more subjects suspected of e.g. illegal, criminal or terrorist activities, whose traffic needs to be intercepted, are all owned by a single operator. For the purpose of this example it is assumed that a LEA is interested in two investigations, the first one involving target identities x and y, and the other involving the target identities x′ and y′, plus the additional identity z. 
         [0028]    In a first step, the Law Enforcement Management Function LEMF identifies for example two e.g. IMEI lists of handsets, list L containing identities x and y, and list K containing identities x′, y′ and z, and passes a request for Lawful Intercept “Request LI” to the Administration Function ADMF of the LI. Then, the Lawful Interception is activated in phase “Activate LI” by providing a single warrant for each list L, K in an Intercepting Control Element ICE (e.g., Gateway GPRS Support Node GGSN, Mobile Switching Centre MSC, etc.) by fetching an e.g. IMEI list of targets, linked to a respective list identifier List_id L and List_id K. Subsequently, the ICE intercepts and filters (“IMEI x”, “IMEI y”) and (“IMEI x′”, “IMEI y′”, “IMEI z”), and generally speaking “IMEI m” and “IMEI n” belonging to a generic list List_id, only relevant traffic coming from or going to the identities, listed in the lists identified by List_id L and List_id K (and generally speaking, any list identified by a List_id). The ICE forwards raw IRIs (“IRI x”, “IRI y”) , (“IRI x′”, “IRI y′”, “IRI z”), and generally speaking “IRI n”, and optionally CC (in general, “CC m”) to the Lawful Interception mediation system LEMF, when traffic data related to any of the IMEI in the target lists reaches the ICE. Data relate to the originator or recipient identities under monitoring. 
         [0029]    Preferably, possible duplicates are filtered out, before providing the intercepted data on the Handover Interface. For example if IMEIx is in communication with IMEIy, in a specified time window and they are in the same list, the intercepted communication will be reported only once on the Handover Interface. Finally, Lawful Interception Mediation System converts the intercepted traffic into the required standard format and sends it to a collection function running at the LEMFs. 
         [0030]      FIG. 4  discloses a signal sequence diagram representing another example of use of the invention in a Lawful Intercept environment, where a list of identities is owned by multiple operators. The exemplary scenario is similar to the one discussed above, and relates to an enhancement of the handover interface HI1 of the Intercept Unit (see  FIG. 1 ) previously discussed which allows to trigger a single warrant with multiple targets included in one or more lists. These lists can be any one of e.g. blacklists, whitelists and greylists. These lists are identified by a list identifier List_id which is also used as a correlation item, thus enhancing the interface HI2 of the Intercept Unit. 
         [0031]    In the second example of  FIG. 4 , the multiple identities of one or more subjects suspected of e.g. illegal, criminal or terrorist activities, whose traffic needs to be intercepted, are owned by different operators, for example a first operator Op 1  and a second operator Op 2 . For the purpose of this example it is assumed that a LEA is interested in two investigations, the first one involving target identities x and y, and the other involving target identities z and w. Target identities x and w are for example owned by the first operator Op 1 , while target identities y and z are for example owned by the second operator Op 2 . 
         [0032]    In a first step, the Law Enforcement Management Function LEMF identifies for example two e.g. IMEI lists of handsets, list L containing identities x and y, and list K containing identities z and w, which are not owned by a single operator. The LEMF passes a request for Lawful Intercept “Request” to the Administration Function ADMF of the LI. Then, in a second phase the lists are transferred from ADMF to a Multi-Operator Mediation Function “Multi-Op MF” (see “Activate Multi-Op LI”). The triggered warrant shall use a special operator identifier associated to the Multi-Op MF. Then, the Lawful Interception mediation system, using the embedded Multi-Operator Mediation Function, provisions multiple warrants repartitioned among several ICEs, (ICE 1 , ICE 2  in the example) each one owned by a specific operator, by fetching an e.g. IMEI list of targets, linked to a respective list identifier List_id L and List_id K. Subsequently, each ICE intercepts and filters only relevant traffic coming from or going to the identities, listed in the lists identified by List_id L and List_id K (in the example ICE  1 : “IMEI x” for List_id L and “IMEI w” for List_id K; ICE  2 : “IMEI y” for List_id L and “IMEI z” for List_id K). The ICE forwards raw IRIs (“IRI x”, “IRI y”, “IRI z”, “IRI w”) , and optionally CCs (not shown in  FIG. 4 ) to the Lawful Interception mediation system LEMF, when traffic data related to any of the IMEI in the target lists reaches the ICE. Data relate to the originator or recipient identities under monitoring. 
         [0033]    Preferably, possible duplicates are filtered out, before providing the intercepted data on the Handover Interface. For example if IMEIx is in communication with IMEIy, in a specified time window and they are in the same list eg. identified by List_id L, the intercepted communication will be reported only once on the Handover Interface. Finally, 
         [0034]    Lawful Interception Mediation System converts the intercepted traffic into the required standard format and sends it to a collection function running at the LEMFs, further correlating the provided data by Operator Identifier. 
         [0035]      FIG. 5  shows a signal sequence diagram representing an example of Data Retention in a simplified environment involving only one operator. Data, e.g traffic data records which includes end users identities such as IP addresses, coming from a Source (e.g. a MultiService Proxy, a Mobile Switching Centre MSC, a Multimedia Messaging Centre MMC, a Radius server, an Email server, a NAT server, etc.), are transferred to the Data Retention system DR Mediation Function/Delivery Function (MF/DF) at a predetermined time interval. Depending on the data source, the data records can contain IP addresses of the users, or IMSI, MSISDN, or any other specific identity indicator. Then, the data are mediated and further transferred (“Mediated Data”) from the Data Retention MF/DF and stored in a Data Retention system storage which can be e.g. a database. 
         [0036]    With reference to  FIG. 6 , according to the present invention, at any moment a LEA may submit a request to query the Data Retention system storage in order to retrieve traffic data information in a certain time window, about various identities, for example IP addresses, which can be grouped in lists. Each list is identified by a List_id, for example List_id L and List_id K. The request from LEA is received by the Data Retention Administrative Function ADMF through HI-A and it is passed on to the Data Retention MF/DF. In a subsequent phase, the Data Retention storage is queried, and then the results are returned to the MF/DF. The MF/DF then delivers the results of the query to LEA, through HI-B. 
         [0037]    The delivered data includes traffic data information related to the identities, e.g. IP addresses, each one of them belonging to the respective list identified by e.g. List_id L and List_id K. 
         [0038]    In this process, possible duplicates, for example when the originator identity and recipient identity are both in the same list which is monitored, are filtered out. For example, if a first IP address k is in communication, in the specified time window, with a second IP address j which is in the same list of IP addresses under investigation, the monitored communication is reported only once on the Handover interface. 
         [0039]    Moreover, the list identifier List-id can be used as a correlation item for the provided traffic query results. 
         [0040]      FIG. 7  shows a signal sequence diagram representing an example of Data Retention in a more complex environment involving several operators. For reasons of clarity, only two operators are shown in  FIG. 7 , but naturally the same concepts apply and can be extended to cover the case of more than two operators. Data, e.g traffic data records which includes end users identities coming from multiple sources (“Source  1 ”, “Source  2 ”), are transferred to the Data Retention system DR Mediation Function/Delivery Function (MF/DF) at a predetermined time interval. As indicated previously, depending on the data source, the data records can contain IP addresses of the users, or IMSI, MSISDN, or any other specific identity indicator. Event Data Records provided from a specific operator are identified by an operator ID, for example a Communication Service Provider CSP ID, which can be agreed upon on a national basis and is unique for each operator within the same country. Then, the data from each operator (“Data  1 ”, “Data  2 ”) are mediated and further transferred (“Mediated Data  1 ”, “Mediated Data  2 ”) from the Data Retention MF/DF and stored in a Data Retention system storage which can be e.g. a database. 
         [0041]    With reference to  FIG. 8 , according to the present invention, at any moment a LEA may submit a request to query the Data Retention system storage in order to retrieve traffic data information or multimedia messaging data information or any other specific information stored in the DR storage system in a certain time window, about various identities, for example IP addresses or IMSIs, which can be grouped in lists. Each list is identified by a List_id, for example List_id L and List_id K. The identities in the lists are associated to a respective CSP ID which identifies the corresponding operator. The request from LEA is received by the Data Retention Administrative Function ADMF through HI-A and it is passed on to a Multi-Operator Mediation Function, which is in charge to associate each identity, for example IP address or IMSI, to the specific CSP ID used for each operator, expanding the single request from LEA into several requests (“Multi Req.”), which are then sent to the Data Retention MF/DF. In a subsequent phase, the Data Retention storage is queried, and then the results are returned to the MF/DF. The MF/DF then delivers the results of the query to LEA, through HI-B. The delivered data includes traffic data information related to the identities, e.g. IMSIs or IP addresses, each one of them belonging to the respective list identified by e.g. List_id L and List_id K, and preferably grouped by CSP IDs. 
         [0042]    Also in this process, possible duplicates, for example when the originator identity and recipient identity are both in the same list which is monitored, are filtered out. For example, if a first IMSI k is in communication, in the specified time window, with a second IMSI j which is in the same list of IMSIs under investigation, the monitored communication is reported only once on the Handover interface. 
         [0043]    Moreover, the list identifier List-id can be used as a correlation item for the provided traffic query results. 
         [0044]    The method and systems which have been described above have several advantages, especially for the LEAs. In fact, by using multi-target warrants/multiple list queries, the investigators can save a significant amount of time and efforts. Moreover, the list identifiers—and more generally the process which has been described—gives the Lawful Enforcement Agencies the possibility to get correlated data, providing a more complete and manageable overview of data related to monitored targets for investigation purposes. The LEA can perform multi-target warrants/multiple list queries using subscribers&#39; identities event when they are not owned by a single operator, therefore helping investigators to save time and effort. 
         [0045]    The description, for purposes of explanation and not limitation, sets forth specific details, such as particular components, electronic circuitry, techniques, etc., in order to provide an understanding of the present invention. But it will be apparent to one skilled in the art that the present invention may be practised in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, devices, and techniques, etc., are omitted so as not to obscure the description with unnecessary detail. Individual function blocks are shown in one or more figures. Those skilled in the art will appreciate that functions may be implemented using discrete components or multi-function hardware. Processing functions may be implemented using a programmed microprocessor or general-purpose computer. The invention is not limited to the above described and in the drawings shown embodiments but can be modified within the scope of the enclosed claims.