Ptt dispatching system and a key remote-destroying method thereof

Filed of the Invention

0001The present invention relates to the field of Push To Talk, PTT, communication system, in particular to a PTT dispatching system and a key remote-destroying method thereof.

Background of the Invention

0002The PTT communication system came out in the 1970s. The earliest PTT communication system was an analog system. Digital PTT techniques sprang up in the global range in the middle 1990s. The digital PTT network appeared in China in the late 1990s. The digital PTT communication techniques have the advantages of high utilization of communication channel and high system capacity, and thus have been widely used.

0003Two main services of PTT techniques are dispatching and group call. The dispatching function of PTT services refers to initiating a call to a certain number of terminals simultaneously to allow these terminals to participate in one call at the same time. The group call function of the PTT services refers to calling a group number at a communication terminal, wherein all the terminals in a group may be connected to one call simultaneously so as to achieve the effect of multi-person speaking at the same time. The terminals mentioned above can be either wired terminals or wireless terminals.

0004In practical applications, the military and the secret organization always have a requirement of encrypting a PTT call for part of the terminals, i.e.. the terminal without encryption authority, even if it is located in the group, can not be connected to a call, such that call privacy can be well ensured. Therefore, a terminal for encryption call must be equipped with an encryption module that is responsible for encrypting and decrypting a call key. For the sake of security, if it is found that a certain terminal can not participate in the encryption call, a dispatching control side may also actively initiate a remote-destroying key to destroy the encryption module of the terminal.

0005In the prior art, however, there is not provided a technique in which the dispatching control terminal actively initiates a key remote-destroying to destroy the encryption module of the terminal, which will affect the safety of the call greatly.

Summary of the Invention

0006The main object of the present invention is to solve the problem of the prior art by providing a PTT dispatching system and a key remote-destroying method thereof, in which a dispatching control terminal may actively initiate a key remote-destroying to a PTT terminal, thereby improving safety of a PTT call.

0007In order to realize the object above, in the present invention there is used the following technical solutions: <ul id="ul0001" list-style="none" compact="compact"><li>a key remote-destroying method for a PTT dispatching system, wherein the PTT dispatching system performs encryption call management of a PTT terminal equipped with an encryption module, comprises the following steps: <ul id="ul0002" list-style="none" compact="compact"><li>A1 the PTT dispatching system initiating a key remote-destroying request to a certain PTT terminal;</li><li>B1 obtaining call information in correspondence with the PTT terminal according to the key remote-destroying request so as to establish a call channel with the PTT terminal;</li><li>C1 generating a key remote-destroying instruction to destroy the encryption module of the PTT terminal; and</li><li>D1 sending the key remote-destroying instruction to the PTT terminal so as to destroy the encryption module thereof, preferably, the key remote-destroying request carries the number information of the PTT terminal; and also comprises the following step:</li><li>E1 the PTT terminal executing the key remote-destroying instruction to its encryption module after receiving the key remote-destroying instruction.</li></ul></li></ul>

0008The PTT dispatching system comprises a dispatch station server, a PTT Dispatch Server, PDS, and a PTT authentication server. The step B 1 includes the following substeps: <ul id="ul0003" list-style="none" compact="compact"><li>B11 the PDS sending a request for obtaining call information in response to a key remote-destroying request initiated by the dispatch station server for a certain PTT terminal, and the PTT Home Register, PHR, returning the call information in correspondence with the PTT terminal in response to the request for obtaining the call information; and</li><li>B12 the PDS establishing a call channel with the PTT terminal according to the call information.</li></ul>

0009The call information comprises user information and a call identification, wherein the user information including a global mobile user identifications and user's current position information.

0010The step B11 includes the following substeps: <ul id="ul0004" list-style="none" compact="compact"><li>B111 the PDS requesting user information from the PTT authentication server;</li><li>B112 the PDS first returning a key remote-destroying response to the dispatch station server after obtaining the user information returned by the PHR and then requesting the call identification from the PTT authentication server; and</li><li>B113 the PHR returning the call identification to the PDS.</li></ul>

0011The PTT dispatching system further comprises a KDC, and the Step C1 includes the following substeps: <ul id="ul0005" list-style="none" compact="compact"><li>C11 the PDS sending a request for obtaining a key remote-destroying instruction to the KDC via the PTT authentication server; and</li><li>C12 the KDC generating a key remote-destroying instruction in response to the request for obtaining the remote-destroying instruction and returning it to the PDS via the PTT authentication server.</li></ul>

0012After the Step E1 there are also included the following steps: <ul id="ul0006" list-style="none" compact="compact"><li>F1 the PTT terminal returning a result of success or failure of key remote-destroying to the PTT dispatching system;</li><li>G1 the PTT dispatching system performing a dispatching terminal process according to the result returned by the PTT terminal;</li></ul>

0013The Step G1 includes the following substeps: <ul id="ul0007" list-style="none" compact="compact"><li>G11 the PDS receiving the result of key remote-destroying of the PTT terminal and sending a result acknowledge request to the KDC via the PTT authentication server;</li><li>G12 the KDC being responsive to the request for result acknowledge and determining whether to update an encryption user list according to the result of key remote-destroying;</li><li>G13 the KDC returning a result acknowledge response to the PDS via the PTT authentication server.</li></ul>

0014In order to realize the aforesaid purposes, in the present invention there is also used the following technical solution: <ul id="ul0008" list-style="none" compact="compact"><li>A PTT dispatching system for realizing key remote-destroying for a terminal comprises a dispatch station server, a dispatching system server, and a KDC; the dispatch station server is configured to initiate a key remote-destroying request for a certain PTT terminal; the dispatching system server is configured to obtain and inquire call information in correspondence with the PTT terminal according to the key remote-destroying request so as to establish a call channel with the PTT terminal; the KDC is configured to generate a key remote-destroying instruction for destroying an encryption module of said PTT terminal; and the dispatching system server is further configured to send the key remote-destroying instruction to the PTT terminal.</li></ul>

0015The dispatching system server comprises a PDS and a PTT authentication server; the PDS is configured to send a request for obtaining call information to the certain PTT terminal according to the key remote-destroying request, receive a call information returned by the PTT authentication server, and establish a call channel according to the call information; the PDS is further configured to a request for obtaining a key remote-destroying instruction to the KDC via the PTT authentication server; and the KDC is configured to return the key remote-destroying instruction to the PDS via the PTT authentication server.

0016The beneficial effects of the present invention are: <ul id="ul0009" list-style="none" compact="compact"><li>Since the PTT dispatching system can actively implement key remote-destroying to a PTT terminal that can not participate in an encryption call in the present invention, the PTT terminal is controlled to destroy its equipped encryption module in response to the key remote-destroying instruction from the PTT dispatching system. If the PTT dispatching system at a dispatching control terminal finds that a certain terminal can not participate in the encryption call, the user terminal is no longer responsible for processing the encryption module thereof, and the PTT dispatching system can actively initiate a key remote-destroying instruction to destroy the encryption module of the PTT terminal. Therefore, such a key remote-destroying manner improves greatly the ability of the PTT dispatching system to manage an encryption call of the PTT terminal in PTT communication, thereby improving the safety of the encryption call.</li></ul>

Brief Description of the Accompanying Drawings

0017<ul id="ul0010" list-style="none" compact="compact"><li><figref idref="f0001">Fig. 1</figref> is a block diagram showing a network of a PTT communication system applied in an embodiment of the present invention.</li><li><figref idref="f0002">Fig. 2</figref> is a flow chart showing a key remote-destroying method for an embodiment of the present invention.</li></ul>

0018The characteristics and advantages of the present invention will be described in detail by the embodiments in combination with the accompanying drawings.

Detailed Description of the Preferred Embodiments

0019In the present invention, when a certain PTT terminal managed by a PTT dispatching system can not participate in an encryption call, the PTT dispatching system at the dispatching control terminal can actively initiate key remote-destroying of the PTT terminal and send an instruction to destroy the equipped encryption module thereof so as to realize safety management of the encryption call.

0020Referring to <figref idref="f0001">Fig. 1</figref>, the PTT communication system applied in the present embodiment comprises logical function modules such as a DSS (Dispatching Service Subsystem), a KDC (Key Distribution Center), a BSS (Base Station Subsystem), a switch subsystem, MSS, (Mobile Switch Subsystem), a PTT terminal, etc., wherein the DSS and the KDC constitute the PTT dispatching system in the present invention. The PTT terminal is coupled to the BSS via an air interface. The DSS and the KDC are coupled to the PTT terminal via the BSS, respectively.

0021The DSS comprises a dispatching system server and a dispatch station server, wherein the dispatching system server further comprises a PDS (PTT Dispatch Server) and a PHR (PTT Home Register) and is mainly responsible for accomplishing a PTT dispatching service.

0022The PDS is a master control point of a PTT call to accomplish processing a PTT dispatching call, including authenticating a PTT user, establishing various PTT calls such as private call and group call, judging a PTT request, etc. In addition, the PDS also receives PTT voice data from a reverse link and distributes it to a corresponding forward link according to call properties.

0023The PHR accomplishes functions of database management and configuration for providing a PTT user with group enrollment and group member enrollment as well as local information of the group member and service authority records of the group member, and functions of call statistics and call charging.

0024The KDC mainly realizes functions of generation, maintenance, and distribution of a key.

0025In the present embodiment, the dispatch station server is a side for initiating a key remote-destroying request for the PTT dispatching system and is responsible for actively initiating a key remote-destroying request for a certain terminal to the PDS.

0026The PDS is a master control point of a PTT call, which sends a request for obtaining call information of the PHR according to the key remote-destroying request, receives the call information returned by the PHR, and establishes a call channel according to user information and call identification thereof, wherein the user information includes global mobile user identification and a user's current position information. The PDS is also responsible for sending a request for obtaining a key remote-destroying instruction to the KDC after establishing the call channel and sending the received key remote-destroying instruction to the PTT terminal. Following a response from the PTT terminal, the PDS receives a key remote-destroying result returned by the PTT terminal, further sends a result acknowledge request to the KDC, and receives a result acknowledge response returned by the KDC after the KDC performs a corresponding process.

0027The PHR is responsible for processing a request of obtaining call information from the PDS, inquiring and returning call information containing user information and call identification to the PDS; it is responsible for transferring a request of obtaining a key remote-destroying instruction from the PDS to the KDC, and returning the key remote-destroying instruction provided by the KDC to the PDS; and in addition, it is also responsible for transferring a result acknowledge request from the PDS to the KDC, and returning a result acknowledge response of the KDC to the PDS .

0028The KDC is responsible for receiving a request of obtaining a remote-destroying instruction of the PDS, generating a remote-destroying instruction according to the request of obtaining the remote-destroying instruction, and sending to the PDS via the PHR; and it is also responsible for receiving a request for result knowledge, determining whether to update an encryption user list according to a remote-destroying result, and returning a result acknowledge response to the PDS.

0029The BSS mainly accomplishes a wireless access function of various PTT services, data services, and general phone services. The BSS is composed of a BTS (Base Transceiver System), a BSC (Base Station Controller), and a PDC (PTT Dispatch Controller), wherein the BTS accomplishes the functions of modulating and demodulating a baseband signal, receiving and transmitting a radio-frequency signal, etc. The BSC accomplishes the allocation of wireless resource, call process, power control, and supporting various switching functions of a terminal. The PDC accomplishes the allocation of wireless resource, dispatching call control, power control, supporting various switching functions of a PTT terminal in different coverage areas, and the aggregation and distribution of a PTT voice data stream.

0030The switch subsystem mainly accomplishes a phone interconnection service, a general phone call service, and part of value-added services. The switch subsystem is composed of a MSC (Mobile Switching Center), a HLR (Home Location Register), etc.

0031Referring to <figref idref="f0002">Fig. 2</figref>, in a PTT communication system, a process of key remote-destroying for a terminal initiated actively and accomplished by the PTT dispatching system at the dispatching control terminal is as follows: <ul id="ul0011" list-style="none"><li>step 201: the dispatch station server, DAS, of the dispatching control terminal actively initiates a key remote-destroying request for a certain PTT terminal to the PTT Dispatch Server, PDS, the request carries number information of the terminal;</li><li>step 202: after receiving the request, the PTT Dispatch Server, PDS requests the PHR for obtaining a user information, which includes global mobile user identification IMSI and a user's current position information;</li><li>step 203: the PTT authentication server, PHR, returns the user information response to the PTT Dispatch Server, PDS;</li><li>step 204: after receiving, the PTT Dispatch Server, PDS, first returns a key remote-destroying response to the dispatch station server DAS;</li><li>step 205: the PTT Dispatch Server, PDS, then requests the PTT authentication server, PHR, for user call identification GID;</li><li>step 206: the PHR generates the user call identification GID and returns a response to the PTT Dispatch Server, PDS;</li><li>step 207: the PTT Dispatch Server, PDS, initiates paging to the terminal by using the obtained call identification GID and user information, and establishes a service channel;</li><li>step 208: the PTT terminal returns a paging response to the PTT Dispatch Server, PDS;</li><li>step 209: the PTT Dispatch Server, PDS initiates a remote-destroying information request to the PHR, viz. requests to obtain a remote-destroying instruction for the encryption module of the PTT terminal;</li><li>step 210: the PTT authentication server, PHR, transfers the remote-destroying information request to the Key Distribution Center, KDC;</li><li>step 211: the Key Distribution Center, KDC generates a remote-destroying instruction for the encryption module of the terminal and returns a remote-destroying information response to the PTT authentication server, PHR;</li><li>step 212: the PHR transfers the remote-destroying information response to the PTT Dispatch Server, PDS;</li><li>step 213: after receiving the response, the PTT Dispatch Server, PDS initiates a key remote-destroying request to the terminal, the request carries the remote-destroying instruction for the encryption module of the terminal.</li><li>step 214: after receiving the key remote-destroying request, the terminal destroys its encryption module by using the remote-destroying instruction carried in the request, and then returns a response regarding whether the remote-destroying is successful to the PTT Dispatch Server, PDS;</li><li>step 215: the PTT Dispatch Server, PDS, sends a request for remote-destroying result acknowledge to PTT authentication server, PHR;</li><li>step 216: the PTT authentication server, PHR, transfers the request for remote-destroying result acknowledge to the Key Distribution Center, KDC;</li><li>step 217: after receiving the request, the Key Distribution Center, KDC updates the maintained user key and user encryption status in real time according to whether the remote-destroying result is successful, and then returns a remote-destroying result acknowledge response to the PTT authentication server, PHR; and</li><li>step 218: the PTT authentication server, PHR, transfers the remote-destroying result acknowledge response to the PTT Dispatch Server, PDS.</li></ul>

0032In the present invention, the encryption module of the terminal could be destroyed instantly, which ensures real-time privacy of an encryption call. Certainly, besides an encryption call management service, the PTT communication system used in the present invention also provides a user not only with various PTT services of the PTT system but also with a traditional general phone service, a short message service, and a data service.

0033The contents above are further a detailed description of the present invention with reference to the preferred specific embodiments, which are not used to restrict the present invention. For those skilled in the art, the present invention may have various variations and alternations within the spirit and principle of the present invention, which are all concluded in the scope of protection of the present invention.