Abstract:
The present invention provides a method for redistributing the license tokens to the traffic nodes to make the license tokens can be efficiently distributed to the traffic node. The method including: collecting usage information of each of the traffic nodes; determining a set of license tokens for each of the traffic nodes; and commanding a first group of traffic node(s) to release license tokens and commanding a second group of traffic node(s) to request license tokens based on the usage information and the set of license tokens. A moderator, used in a license controlling system which can efficiently redistribute the license tokens among the traffic nodes, is provided and a controlling system which including this moderator is also provided.

Description:
This application is the U.S. national phase of International Application No. PCT/CN2009/001304 filed 23 Nov. 2009 which designated the U.S., the entire contents of which is hereby incorporated by reference. 
     TECHNICAL FIELD 
     The present invention relates, at least in part to the field of license management. In particular, the present invention relates to license redistributing in a license management system. 
     BACKGROUND 
     License management is used for controlling the use of software applications. A software application is designed with a built-in function that allows it to operate only when an appropriate license is available. 
     In comparison with the on-off feature-based license management, the usage-based license management is becoming more and more popular. One type of the usage-based license management is capacity-based controlling system in which the number of transactions per a period is restricted. 
     A basic license controlling system based on the capacity typically includes one or more traffic nodes that handle the incoming traffic and provide telecom services for terminals in the telecom network, and license server that controls all traffic nodes to use the traffic legally, wherein each traffic node may provide at least one type of service, such as only Short Message Service (SMS), or SMS and email service. A large-scale license controlling system which comprises more license servers and traffic nodes is established for big customer, as shown in  FIG. 1 , therein wherein the network is divided into sub-networks either logically according to the traffic type or geographically according to the governing area, and the license servers are connected with each other. Typically, one license server in each sub-network serves the license requests from its own sub-network. However, other servers can take over that requests when the server failed in dealing with it. 
     Since the validation of service usage is performed against the number of allowed license tokens on each traffic node, wherein the license tokens are obtained from license server, it is actually impracticable to obtain the license tokens from the license server each time when there is a new incoming request to traffic node from terminal via the telecom network. 
     A widely used solution is shown in  FIG. 2 . In this solution, a number of license tokens are even distributed to each traffic node for example during the initializing. Refer to  FIG. 2 , numbers of license tokens  200 , which are used to control the traffic capacity  210  of incoming requests for services provided by traffic nodes  20 , are preserved at each of traffic nodes  20 . Once the traffic capacity  210  of the incoming requests exceeds the preserved license tokens  200  at any traffic node, for example, the traffic node  203 , the traffic node sends a request for renewing license tokens to a license server  22 . In case of failing to renew license tokens, the exceeded service requests is blocked or queued up, while most of the preserved license tokens  200  at the traffic node  201  are left unused for less traffic capacity of incoming request. Borrowing unused license tokens from other traffic nodes are allowed in some case, but it is impracticable for the complex operation. 
     A post-validation mechanism, allowing the traffic of incoming requests to be passed before license validation and deducting the license tokens corresponding to the actual usage from the license server after a certain timeframe, is used in another solution. Comparing with so called pre-validation mechanism (every traffic of incoming request will be validated against the license tokens before further process of the traffic request) used in above mentioned solution, such post-validation mechanism avoids the problem that caused by even distribution of license tokens at the beginning in an unpredicted unbalanced traffic environment, as well the complexity of token borrowing between the traffic nodes. 
     However, after the initial distribution of the license tokens in pre-validation mechanism or deducting the license tokens in post-validation, both pre-validation and post-validation mechanism utilizes the “first come first served” approach (i.e. the requests from the traffic nodes are served in the order of their reaching the license sever) to make the traffic nodes obtain license tokens from the license server. Under this approach, once license tokens at the license server are used up, any request for tokens, no matter from which traffic node it come&#39;s, will be refused or queued up without considering priority, importance or demand of the request until the occupied license tokens are released and made available again. This manner may be suitable in a single-type service environment where only one type of service is provided by traffic nodes or each of traffic nodes plays equal important role in the network. But it is unacceptable in a mixed-service environment, where more than two types of service are provided by one or more traffic nodes or the traffic nodes obtain the license tokens from the same license server in a manner of “first come first use” even if they hold different priorities or weights, in a license controlling system. 
     The prior art way of distributing the license tokens in the “first come first served” approach may cause that the license controlling system, due to missing license in some nodes, can not handle the more prioritized requests while it at the same time handles less prioritized requests. 
     SUMMARY 
     In practice, certain traffic node should deserve a higher priority or importance for its service or location and so on. Accordingly, it would be desirable to provide a method and a system for providing an efficient redistribution mechanism in a license controlling system to overcome the above mentioned disadvantages. 
     Therefore, it is one object of the present invention to address the above disadvantages by providing a method, a moderator and a license controlling system for efficiently redistributing the license tokens among the traffic nodes. 
     According to one aspect of the invention, a method of redistributing the license tokens to the traffic nodes is provided, and the method comprise the steps of: collecting usage information of each of the traffic nodes; determining a set of license tokens for each of the traffic nodes; and commanding a first group of traffic node(s) to release license tokens and commanding a second group of traffic node(s) to request license tokens based on the usage information and the set of license tokens. 
     Wherein the usage information includes a traffic capacity of each of the traffic node and the number of existing license tokens at each of the traffic node. 
     Wherein the set of license tokens for each traffic node is determined by calculating the total number of tokens in the set of license tokens based on the traffic capacity and the number of existing license tokens. 
     Preferably, the method further includes collecting the number of available license tokens at a server of the license controlling system before the determining step. 
     Wherein the set of license tokens for each traffic node is determined by calculating the total number of tokens in the set of the license tokens based on the traffic capacity, the number of existing license tokens and the collected number of available license tokens at the license server. 
     Wherein a redistribution algorithm is preconfigured, and the redistribution algorithm is priority based, demand based or weight based distribution algorithm. 
     Wherein the first group of traffic node(s) includes the traffic node where the number of the existing license tokens are more than the total number of tokens in the set of license tokens; the second group of traffic node(s) includes the traffic node where the number of the existing license tokens are less than the total number of tokens in the set of license tokens. 
     Preferably, the method further includes triggering the redistributing before collecting the usage information of each of the traffic nodes. 
     As one aspect, the redistributing is triggered by a request from any traffic node. In this case, the method further includes checking whether the redistribution requested is allowed before triggering the redistributing, by comparing the interval between the request and the last request with a predetermined period of time, if the interval is more than or equal to the predetermined period of time, the redistribution requested is allowed. 
     As another aspect, the redistributing is triggered by receiving triggering information from a settable timer. In this case, the method further includes setting the settable timer according to a timing algorithm. 
     According to one aspect of the invention, a moderator used in a license controlling system is provided, which includes: an input unit; an output unit; a processing unit which is adapted to collect usage information of each of the traffic nodes and determine a set of license tokens for each of the traffic nodes; and a memory portion for at least storing the usage information and the set of license tokens. 
     Wherein by the output unit, the processing unit further commands a first group of traffic node(s) to release license tokens and commands a second group of traffic node(s) to request license tokens according to the usage information and the set of license tokens. 
     Wherein the usage information collected by the processing unit includes the traffic capacity of each of the traffic nodes and the number of existing license tokens at each of the traffic nodes. 
     Wherein the processing unit determines the set of license tokens for each the traffic node by calculating the total number of tokens in the set of license tokens on the basis of traffic capacity and the number of existing license tokens. 
     Wherein the processing unit further collects the number of available license tokens at a server of the license controlling system by the input unit. 
     Wherein, by calculating the total number of tokens in the set of license tokens on the basis of the traffic capacity, the number of existing license tokens and the available license tokens, the processing unit determines the set of license tokens for each traffic node. Preferably, a redistributing algorithm, which can be used to calculate the total number of tokens in the set of license tokens, is preconfigured to the moderator, and the redistributing algorithm is priority based, demand based or weight based distribution algorithm. 
     Wherein the first group of traffic node(s) includes the traffic node where the number of existing license tokens are more than the total number of tokens in a set of the license tokens; the second group of traffic node(s) includes the traffic node where the number of existing license tokens are less than the total number of tokens in the set of license tokens. 
     Wherein, by the input unit, the processing unit receives a request for redistribution from any of the traffic node before it collects the usage information. 
     Wherein the process unit then checks if the request for redistribution is allowed by comparing the interval between said request and the last request with a predetermined period of time, if the interval is more than or equal to the predetermined period of time, the request for redistribution is allowed. 
     Wherein, the process unit further updates the last redistributing time. Preferably, the moderator includes a settable timer for setting the redistributing time. 
     Wherein, the process unit receives triggering information from the settable timer. 
     Wherein, the settable timer updates the redistribution time for next redistributing. 
     According to another aspect of the invention, a license controlling system is provided, which includes traffic nodes for handling incoming traffic from telecom network, and providing services to terminals requesting the services via the network; license server for sending license tokens to the traffic nodes and receiving the license tokens released by any of the traffic nodes; and a moderator above described. 
     According to a yet aspect of the invention, a server for a license controlling system, which is integrated with a moderator above described is provided. 
     Further, a license controlling system which includes plurality of traffic nodes and a server above described is also provided. 
     Further, a computer program, stored on a tangible storage medium, for redistributing license tokens to traffic nodes in a license controlling system is provided, and the program comprises executable instructions that cause a computer to collect usage information of each of the traffic nodes; determine a set of license tokens for each of the traffic nodes; and command a first group of traffic node(s) to release license tokens and commanding a second group of traffic node(s) to request license tokens based on the usage information and the set of license tokens. 
     A computer readable medium including logic for redistributing license tokens to traffic nodes in a license controlling system is also provided, wherein the logic is operable to collect usage information of each of the traffic nodes; determine a set of license tokens for each of the traffic nodes; and command a first group of traffic node(s) to release license tokens and commanding a second group of traffic node(s) to request license tokens based on the usage information and the set of license tokens. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic diagram illustrating a conventional license controlling system based on the capacity; 
         FIG. 2  is schematic diagram illustrating a widely used conventional license controlling system; 
         FIG. 3  is a block diagram showing the license controlling system according to one example of the present invention; 
         FIG. 3A  is a block diagram showing the moderator  31  in more detail; 
         FIG. 4  is a step diagram of a redistributing procedure of one example according to the present invention; 
         FIG. 5  is a step diagram of a procedure of one example according to the present invention which is applied to the pre-validation operation mode; 
         FIG. 5A  depicts the step  50  of  FIG. 5  in more detail; 
         FIG. 5B  depicts the step of  52  of  FIG. 5  in more detail; 
         FIG. 5C  depicts the step of  53  of  FIG. 5  in more detail; 
         FIG. 6  is a block diagram showing the license controlling system according to another example of the present invention; 
         FIG. 7  is a step diagram of a procedure used in a post-validation mode according to the present invention; and 
         FIG. 7B  depicts more details of the step  71 . 
     
    
    
     DETAILED DESCRIPTION 
     Briefly described, the present invention, at least in part, provides a solution that the license tokens can be efficiently distributed after the initial distribution, based on the requirement of each traffic node. 
     The term “moderator” herein refers to a device which is used to determine a set of license tokens for each of traffic nodes and command the traffic nodes to release or request more license tokens after comparing the set of license tokens with the existing license tokens at each of traffic nodes. 
       FIG. 3  is a block diagram showing the license controlling system according to one example of the present invention. License controlling system  3  includes a license server  32 , a moderator  31 , and plurality of traffic nodes  30 . The license server  32  can be any computer-based server adapted to store the license tokens which may installed by the operator. Further, the license server  32  is adapted to send the license tokens to traffic nodes  30 , and receive the license tokens released by the traffic nodes  30 . 
     The traffic nodes  30  comprises plurality of traffic nodes TN 1   301 , TN 2   302 , and TN 3   303  for handling the traffic of incoming requests and providing the telecom services, such as short massages, emails, file transfers and other network services, for terminals (not shown), such as mobile phone, fixed-phone, PDA, PCs and so on, or other network nodes like MSC, CSCF etc., via the telecommunication network. Each of the traffic nodes  30  can be computer-based server and adapted to request and receive the license tokens from the license server  32  and release the license tokens to the license server  32 . In some case, the traffic node can also be referred as a traffic processing unit in the concept of one product with several loads sharing servers in the system. It can be understood that the traffic nodes  30  may comprise more traffic nodes than the number of traffic nodes shown in  FIG. 3 , or less than. 
     The moderator  31  is adapted to collect the usage information from each of the traffic nodes  30 , wherein the usage information includes: the number (T i ) of existing license tokens at each of the traffic nodes  30  and/or the traffic capacity (V i ) of each traffic node. The moderator  31  may collect the number (T s ) of available license tokens from the license server  32 . Further, the moderator  31  is adapted to calculate the suggesting number (Si) of license tokens for each of the traffic nodes  30  based on the total number (ΣT i +T s ) of the license controlling system  3  and/or the traffic capacity (V i ) of each traffic node. (As used herein, the terms “a/the suggesting license tokens” represent “a/the set of license tokens”, and the terms “a/the suggesting number of license tokens” represent “a/the total number of tokens in the set of license tokens”.)The moderator  31  then commands the first group of traffic nodes, in each of which the suggesting number of license tokens is less than the number of its existing tokens, to release additional tokens (R i , R i =T i −S i ) to the license server  32  and/or commands the second group of traffic nodes, in each of which the suggesting number of license tokens is more than the number of its existing tokens, to request more license tokens (Ri, Ri=Si—Ti) from the license server  32 . In present description, the subscript i represents a serial number of the traffic node. 
       FIG. 3A  is a block diagram showing the moderator  31  in more detail. Refer to  FIG. 3A , the moderator  31  includes an input/output unit  310 , which can include an input unit  310 A and an output unit  310 B, is configured to receive information from the traffic nodes  30  and/or the license server  32  by the input unit  310 A and to send information to the traffic nodes  30  and/or the license server  32  by the output unit  310 B, wherein the information at least includes the information relating to the existing number of license tokens T i , the suggesting license tokens S i , the additional license tokens R i (R i =T i −S i ), and more license tokens R i  (R i =S i −T i ); a processing unit  312  for operating the redistributing of the license tokens; and a memory portion  314  for storing the information that can be accessed by the processing unit  312 , such as the number of existing license tokens etc., wherein the memory portion  314  can be a cache, a buffer, or a RAM, alternatively, the memory portion  314  may be a memory separated from the moderator itself. 
     As illustrated with the solid box of  FIG. 3 , the moderator  31  is separated from the license server  32 . And the dotted box illustrates another alternative architecture where the moderator  31  may be integrated with the license server  32 . 
     It is noted that the moderator  31  directly communicates with the license server  32  by connection  102  in above controlling system  3 , however, in practice, the controlling system  3  can run without the connection  102 . In that case, the total number of license tokens in this controlling system  3  can be preconfigured to the moderator  31  for example by the operator, for example, said total number of license tokens is configured to the memory portion  314  of the moderator  31  when it is configured to the license server. So that the process unit  312  obtains the total number of the licenses tokens of the controlling system  3  by only accessing the memory portion  314  when calculating the suggesting number of the license tokens, rather than accessing the license server  32 . 
       FIG. 4  is a step diagram of a redistributing procedure of one example according to the present invention. In first step of  40 , once the processing unit  312  of the moderator  31  receives triggering information by the input/output unit  310 , the moderator  31  starts the redistribution. The triggering information can either come from outside of the license controlling system  3 , e.g. by an operator, or inside, e.g. by a traffic node or by a timer (not shown in  FIG. 3 ). In then step of  42 , the processing unit  312  collects the usage information from each traffic node and receives said information by the input/out unit  310 ; moreover, the information may be stored in the memory portion  314  wherein the usage information includes: the number (T i ) of existing license tokens at each of the traffic nodes  30  and/or the traffic capacity (V i ) of each traffic node. And in step of  44 , the processing unit  312  collects the number (T s ) of available tokens at the license server  32 . In step of  45 , the processing unit  312  further determines the suggesting license tokens for each of traffic nodes  30  by calculating the suggesting number (S i ) of license tokens based on the number (T i ) of existing license tokens at each traffic node, the number (T s ) of available tokens at the license server, and/or the traffic capacity (V i ) of each traffic node according to a preconfigured redistribution algorithm, wherein the algorithm may be stored in an outside memory device, such as a hardware apart set apart from the moderator, and loaded to the moderator  31  for being processed by the processing unit  312 , and the algorithm also can be stored in the memory portion  314  and invoked by the processing unit  312  when needed. In next step of  46 , the processing unit  312  commands the first group of traffic nodes, in each of which the suggesting tokens are less than its existing tokens, to release additional tokens (R i , R i =T i −S i ) to license server  32  and commands the second group of traffic nodes, in each of which the suggesting tokens are more than its existing tokens, to request more tokens (R i , R i =S i −T i ) from the license server  32  by the input/output unit  312 . 
     When there is no connection  102  between the sever  32  and the moderator  31 , and the total number of the license tokens is preconfigured to the moderator  31 , then the step of  44  can be skipped. In this case, the processing unit  312  determines the suggesting license tokens for each of traffic nodes  30  by calculating the suggesting number (S i ) of license tokens based on the number (T i ) of existing license tokens at each traffic node and/or the traffic capacity (V i ) of each traffic node according to a preconfigured redistribution algorithm. The redistribution algorithm used to calculate the suggesting number of license tokens can be priority based, demand based and weight based algorithm. 
     Priority Based: 
     In this algorithm, each of the traffic nodes  30  has been assigned a priority order and the license tokens are assigned based on the capacity according to the order. For example, assuming that the traffic node TN 3   303  has the top priority, the traffic node TN 1   301  has the lowest and the traffic node TN 2   302  has a middle priority; and the traffic capacity of each traffic node is 500 for TN 1 , 300 for TN 2  and 900 for TN 3 . Then, in the case that the total number of license tokens is 1000, TN 1   301  gets 0, TN 2   302  gets 100 and TN 3   303  gets 900. 
     Demand Based: 
     The license tokens will be redistributed according to the actual demand of traffic capacity. In the case that the license tokens of overall demand is not more than the total license tokens, each of the traffic nodes obtains the license tokens as its demand. However, if the total number of license tokens is less than the license tokens of overall demand, the license tokens is redistributed based on the proportion of the demand for each traffic node separately according to: 
     
       
         
           
             
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     Weight Based: 
     Each traffic node is assigned with a weight coefficient (P i ) representing an allowed capacity proportion for it. For the traffic nodes where the actual traffic capacity is below the allowed capacity proportion, all unused license tokens is distributed in a percentage of overall demands. Thus, those traffic nodes, which have used up their own allowed capacity proportion and still demand more, obtain the additional license tokens from all unused license tokens. The formula for the weight based distribution is given hereafter: 
     
       
         
           
             
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     Note that the distribution algorithm above described examples is only used to illustrate this invention, rather than to limit the invention. 
     It can be appreciated that the traffic capacity in any algorithm, which is the traffic capacity collected by the moderator processing unit  312  in step of  42 , can comprise two parts, one is the actual capacity, and the other is margin capacity which is configured to each traffic node to avoid the traffic node frequently sending a request for redistribution when the traffic capacity of incoming request to the traffic node keeps increasing. 
       FIG. 5  is a step diagram of a procedure of one example according to the present invention which is applied to the pre-validation operation mode. For following description, please also refer to  FIGS. 3 and 3A . In the first “initialization” step of  50 , the license tokens at license server  32  are distributed according to a pre-configured proportion to each traffic node. In second “renewal” step of  52 , the traffic node, whose traffic capacity is about to reach the license tokens obtained during the initialization, sends a request to the license server  32  for renewing license tokens. In further “redistribution” step of  54 , the redistribution procedure is executed to redistributing the license tokens among the traffic nodes, after said traffic node fails to renew license tokens from the licenser server  32 . 
       FIG. 5A  depicts the step of  50  of  FIG. 5  in more detail. As shown in  FIG. 5A , the processing unit  312  of the moderator  31  sends a command to obtain the total number of license tokens from license sever  32  (step  50 A) and receives the feedback information by the input/output unit  310 . Then the processing unit  312  determines the number of initial tokens to be preserved, which each traffic node will request from the license server  32 , by multiplying the total number of license tokens with a pre-configured proportion for each of traffic nodes  30  (step  51 A). For example, the total number of license tokens is 1000, and the proportions for traffic node TN 1   301 , TN 2   302  and TN 3   303  are 20%, 30% and 10% respectively, then the numbers of initial tokens for each traffic node are 200 for TN 1 ,  300  for TN 2  and 100 for TN 3 . It should be noted that total proportion of all traffic nodes should less than or equal to 100%, it also can be understood that not all license tokens on the license server  32  have to be distributed to the traffic nodes  30 . The moderator  31  then commands each of traffic nodes  30  requests its initial tokens from the license server  32  (step  52 A). 
       FIG. 5B  depicts the step of  52  of  FIG. 5  in more detail. Note that a threshold can be pre-configured into each of traffic nodes  30 . Once the number of the left over tokens, given by subtracting the number of license tokens corresponding to the capacity being used from the number of existing license tokens (note that the existing license tokens is the initial tokens if the traffic node do not release any license tokens), is equal to the threshold in any traffic node, the traffic node sends a request to the license server  32  for renewal tokens, for example traffic node TN 1   301  requests for renewal tokens (step  51 B), wherein the renewal tokens can be a configured “step”(s), such as  10  and so on. In the case that the traffic node achieves its renewal tokens, the renewing still can be started upon the threshold is reached again for the traffic capacity of incoming request keeps increasing. As shown in step of  52 B, the traffic node TN 1   301  requests renewal license tokens from the license server  32  again. In this example, the traffic node  303  also requests for renewal tokens (step  53 B), and it fails, as shown in step  54 B, since there is no enough license tokens available in the license server  32  to satisfy the request. Thus the traffic node TN 3   303  then sends a request (step  55 B) for redistribution to the moderator  31 . Note that any traffic node, which fails to obtain the license tokens in renewal step, can request for redistribution of the license tokens. 
       FIG. 5C  depicts the step of  54  of  FIG. 5  in more detail. The redistribution is triggered when the moderator  31  receives the request for redistribution from traffic nodes  303 , as shown in step  51 C. Then the processing unit  312  checks whether this redistribution is allowed (step  52 C). A scale time is predetermined to avoid the redistribution too frequently especially when the overall traffic capacity exceeds the total license tokens, if the interval between two redistributions in a row is more than or equal to the scale time, the redistribution is allowed, or refused. In this example, the redistribution is allowed. The processing unit  312  further collects the number (T i ) of existing license tokens from each of the traffic nodes and the traffic capacity (Vi) of each traffic node  30  (step  53 C). Then the processing unit  312  obtains the number (T s ) of available license tokens from the license server  32  (step  54 C). Then the processing unit  312  calculates the suggesting number (S i ) of license tokens for each traffic node according to the redistribution algorithm based on Ti, and Ts, and/or V i  (step  55 C). After comparing the suggesting number (S i ) of license tokens with the existing tokens (T i ), the moderator  31  then determines the first group of traffic nodes and the second group of traffic nodes, wherein the first group of traffic nodes consists of the traffic node where the number of existing license tokens are more than the suggesting number of license tokens and the second group of traffic nodes consists of the traffic node where the number of existing license tokens are less than the suggesting number of license tokens. The processing unit  312  then commands each of the first group of traffic nodes releases the additional license tokens Ri (R i =T i -S i ) to the licenser server  32  (step  56 C), for example, commands the traffic node TN 1   301  and traffic node TN 3   303  to release their additional license tokens respectively. The processing unit  312  also commands the second group of traffic nodes, only TN 2  in this example, to request more license tokens Ri (R i =S i -T i ) from the license server  32  (step  57 C). Finally, the moderator  31  updates the last redistribution time (step  58 C). 
     In the case that all license tokens at the license server  32  are distributed to the traffic nodes  30  in initialization step, the renewal step can be skipped. 
       FIG. 6  is a block diagram showing the license controlling system  6  according to another example of the present invention. Regarding  FIG. 6 , by using identical reference numerals to denote components identical to the example shown in  FIGS. 3 and 3A , their description is omitted. In comparison with  FIGS. 3 and 3A , the moderator  31  in this example further includes a settable timer  316  for setting a redistribution time. A triggering information is sent to the processing unit  312  upon the redistribution time arrives, that is, the processing unit  312  receives the triggering information from the settable timer when the redistribution time arrives. And the timer  316  updates the redistribution time for next redistribution based on a pre-configured timing algorithm. Comparing with the procedure which is shown in  FIG. 4 , the redistribution procedure executed in this license controlling system is executed not depending on the requesting from the traffic node, but on the arriving of redistribution time of the settable timer  316 . 
     With reference to  FIG. 6 , a redistribution time is set by the settable timer  316 . Once the redistributing time arrives, the redistribution is started. Then the processing unit  312  collects the usage information of each of the traffic nodes  30  wherein the usage information includes the traffic capacity (V i ) of each traffic node and the number (T i ) of existing license tokens at each of the traffic nodes  30 . The moderator  31  may collect the number (T s ) of available license tokens at the license server  32  (if the connection  102  between the process unit and the license server is established). After receiving the usage information and the available license tokens, the process unit  312  calculates the suggesting number of license tokens for each of traffic nodes  30  according to a preconfigured redistributing algorithm based on the usage information V i  and T i  and the total license tokens (ΣT i +T s ), or based on part of the usage information like Ti and the total license tokens. Then the moderator  31  commands the first group of traffic nodes, which consists of the traffic node where the suggesting tokens are less than the existing tokens, to release additional tokens R i  (R i =T i −S i ) to license server  32  and commands the second group of traffic nodes, which consists of the traffic node where the suggesting tokens are more than the existing tokens, to request more tokens R i  (R i =S i −T i ) from the license server  32 . Then the settable timer  316  sets time for the next redistribution. 
       FIG. 7  is a step diagram of a procedure used in a post-validation mode according to the present invention. In the first “initialization” step  70 , each of the traffic nodes  30  receives and processes the traffic of incoming request without the license validation from the license server, and the redistribution time in the settable timer  316  for the first redistribution is set as t 1 . In the next “redistribution” step  71 , the redistribution procedure is implemented when the processing unit  312  receives triggering information from the settable timer  316 . It is noted that the license tokens for each of the traffic nodes  30  are deducted from the licenser server  32  before the redistribution step according to the actual capacity usage at a time, wherein the actual capacity usage can be collected by the moderator  31 . How the license is performed and the license tokens are deducted is not the scope of the claimed invention and, thus, the procedure will not be described any further in this document. 
     Refer to  FIG. 7B  for more details of the step  71 . The redistribution is started when the redistribution time of the settable timer arrives (step  71 B). The processing unit  312  further collects the number (T i ) of existing license tokens from each of the traffic nodes  30 , and collects the traffic capacity (V i ) of each traffic node (step  72 B). Then the processing unit  312  obtains the number (T s ) of available license tokens at the license server  32  (step  73 B). Then the processing unit  312  further calculates a suggesting number (S i ) of the license tokens for each traffic node according to the redistribution algorithm based on T i , and T s , and/or V i  (step  74 B). Further, the processing unit  312  determines the first group of traffic nodes, in each of which the number of existing license tokens of each traffic node is more than the suggesting number of license tokens and the second group of traffic nodes, in each of which the number of existing license tokens of each traffic node is less than the suggesting number of license tokens, by comparing the suggesting number of license tokens with the existing number of license tokens. The processing unit  312  then commands each of the first group of traffic nodes  30  releases the additional license tokens R i  (R i =T i −S i ) to the license servers  32  (step  75 B), for example, commands the traffic node TN 1   301  to release R 1  license tokens and the traffic node TN 3   303  to release R 3  license tokens. The processing unit  312  also commands each of the second group of traffic nodes  30 , for example TN 2   302 , to request more license tokens R i  (R i =S i −T i ) from the license server  32  (step  76 B). Finally the settable timer  316  updates its time of the settable timer  316  for next redistribution (step  77 B) according to a pre-configured time algorithm. 
     In brief, the pre-configured time algorithm is based on the total traffic capacity collected, the bigger the traffic is, the smaller the time step is. In the case of a minimal time interval and maximal time interval set in advance, the timing algorithm for the next redistribution time t k  is shown: 
     
       
         
           
             
               
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             Where the total traffic capacity of all the traffic nodes V k-1  is modulated to numeric: 0,1,2 , . . . . 
             V max  is the total allowed traffic capacity in the license controlling system; 
           
         
       
    
     K={0, 1, 2, . . . } and λ, Δt min , Δt max  and V max  are settable. 
     The algorithm above mentioned is only an example for illustrating the invention, and it should not be used to limit the claimed invention. It could be appreciated that the redistributing procedure which is shown in  FIG. 7  can also be used in pre-validation mode with a little modification, for example, setting a settable timer to the controlling system  3  and thus the redistribution procedure is started by receiving triggering information from the timer instead of request from traffic nodes. 
     The redistributing procedure shown in  FIG. 5C  can also be used in post-validation mode, e.g. after the first redistribution is triggered by the time arriving of the settable timer, the next redistribution can be triggered by request from the traffic nodes. 
     In addition, as an alternative, the calculating step of  55 C and  77 B can be executed by the respective traffic node. In this case, each traffic node calculates the suggesting number of license tokens according to the algorithm (which can be pre-configured in each traffic node in advance) based on its own existing number of license tokens and its own traffic capacity, and then send the result of this calculating to the moderator. As the moderator under this situation, it determines the first and second groups of traffic nodes by only comparing the number of existing license tokens and the suggesting number of tokens. Moreover, in this case, the moderator has not to collect the traffic capacity of each traffic node. 
     Although the exemplary embodiments have been described above, the present invention is not limited to these exemplary embodiments. The exemplary embodiments may be used in combination or each of the embodiments may be partially modified, with the spirit and scope the present invention. 
     While the preferred exemplary embodiments of the present invention have been described using specific items, such description is for illustrative purpose only, and it is to be understood that changes and variations may be made without departing from the spirit and scope the following claims.