The method of overloading control in the CDMA cellular communication system
The present invention relates to the method for overloading control in a kind of mobile communication system, especially the method for overloading control in CDMA (code division multiple access) cellular communication system.
At present, in mobile communication system, for example in the cdma cellular communication system, the amount of information that system need handle is among the dynamic change, may be owing to the reasons such as time delay of the increasing of amount of system information, process information, make system's overload operation, thereby cause the decline even the collapse of systematic function.Therefore, must control, to guarantee the normal operation of system to system loading.US Patent specification US5440741 discloses the method (Software overload control method) of a kind of software overloading control in a kind of communications network system.Its processing method is to be in overload state when software systems, judges it is to postpone to handle or the request message that refusal is external according to the degree of system overload.If the method according to US Patent specification US5440741 is handled the message of being received, if postpone to handle the request message of being received, when the initiator receives response message, may be overtime because of the timer of request message, this response message is invalid.US Patent specification US5867787 has also provided the method (Overload control for anintegrated MSC/HLR switch) of the overloading control of MSC/HLR (mobile switching centre/attaching position register) switch among a kind of GSM (global system for mobile communications), for the HLR module, when its judgement system is in overload state, just refuse the access of all TCAP (TCAP Transaction Capability Application Part) message.
No matter the overladen method of above-mentioned treatment system is to postpone to handle or all external request messages of refusal, inevitably causes the decline of system effectiveness and the reduction of performance.
At above-mentioned prior art problems, the objective of the invention is, providing a kind of can control effectively to the overload in the cdma cellular communication system, and makes this system keep the method for overloading control in the cdma cellular communication system of higher data disposal ability and performance.
For achieving the above object, the present invention adopts the method for overloading control in a kind of CDMA cellular communication system, and this method comprises the following steps:
(1) TMD of HLR (attaching position register) front end processor (TCAP message control module) receives TC_INVOKE_REQ (transaction-capable operation requests, the i.e. TC operation requests) solicited message that transmits from TCAP;
(2) obtain the occupation rate of the CPU (central processing unit) of current front end processor, and obtain the flow control level of front end processor according to the occupation rate of this CPU;
(3) obtain the processing speed of MAP (MAP) processor, and obtain the flow control level of this MAP processor according to the processing speed of MAP processor;
(4) from the flow control level of the MAP processor of the flow control level of the HLR front end processor of above-mentioned steps (2) and above-mentioned steps (3), choose the maximum as the flow system flow controlled stage;
(5) when the flow system flow controlled stage be the minimum flow controlled stage, then message all inserts, and changes step (10) and continues operation;
(6) when the flow system flow controlled stage be the maximum flow controlled stage, then message is all refused, and changes step (9) and continues operation;
(7) when the flow system flow controlled stage is between minimum flow controlled stage and maximum flow controlled stage, appoints and to get a random number and maximum flow level and deduct the flow system flow controlled stage and add 1 again and ask mould.
(8) judge whether this mould is zero, as be zero, change step (9) and continue operation, continue operation otherwise change step (10);
(9) the TC_INVOKE_REQ request message that receives from TCAP of the TMD of HLR front end processor refusal, and send out TC_U_ABORT message to TCAP;
(10) TMD of HLR front end processor sends the TC_INVOKE_REQ request message to HLR MAP processor, by the MMD continuation of HLR MAP processor this information is handled.
From such scheme as can be seen, because adopting, the present invention in HLR system front end processor, carries out overloading control, the access of control traffic carrying capacity has guaranteed the successful processing of access service by the access of refusing some traffic carrying capacitys, thereby has avoided the further decline of HLR disposal ability.The present invention simultaneously is when carrying out overloading control, from the flow control level of the flow control level of HLR front end processor and HLR MAP processor, choose the maximum as the flow system flow controlled stage, and abandon the basis of rate as a certain business of refusal with it, promptly consider the disposal ability of HLR front end processor itself, it is the current CPU occupation rate of HLR front end processor, consider the disposal ability of HLRMAP processor again, it is the average duration that the MAP processor is handled a business, thereby the present invention not only can intercept the access of partial service in system's overloading control, avoid the further decline of HLR system processing power, when the HLR disposal ability strengthened, the access of traffic carrying capacity can be increased.Therefore, the present invention can control effectively to the overload in the cdma cellular communication system, can make system keep higher data disposal ability and performance again.
The present invention is further illustrated below in conjunction with drawings and Examples.
Fig. 1 is a schematic flow sheet of the present invention;
Fig. 2 is CDMA HLR system's front end processor and HLR MAP processor logical construction schematic diagram;
Fig. 3 is the flow control rank table that the CPU occupation rate according to embodiment of the invention HLR front end processor draws;
Fig. 4 is the flow control rank table that the CPU processing messages speed according to embodiment of the invention HLR MAP processor draws;
Fig. 5 is that the message of the different flow control hierarchy of the embodiment of the invention inserts ratio.
At first with reference to figure 2.The HLR system adopts distributed storage, load sharing processing method.This system is divided into front end processor and MAP processor on hardware configuration, wherein comprise MTP (message transmission module) in the front end processor, SCCP (signaling link control module), TCAP (transaction application module), TMD (front end processor Message Distribution Module), the MAP processor comprises MMD (MAP processor message control module), TM (conversion layer module), MAP (mobile application part sub-module), by designing the MD module on the upper strata of front end processor TCAP module and the lower floor of MAP processor TM module, be TMD module and MMD module, function by TMD module and the common MD module of forming of MMD module is exactly to realize two-way load balancing, the dynamically flow direction of control messages between front end processor and HLRMAP node.As seen, must carry out overloading control in the upper strata of TCAP module TMD module and could guarantee that HLRMAP keeps certain processing capabilities under the overload situation.If not in the control of loading of the TMD of HLR front end processor module, when HLR MAP processor for some reason, chronic etc. as reading database, can not in time handle the information of being accepted, follow-up is still constantly sent, the processing delay of every message is increased, so that last every message all can't in time be handled, the disposal ability of whole system may reduce to 0, if carry out overloading control in the TMD module, when the disposal ability of HLR drops to certain the time, by refusing the successful processing that some message just can guarantee another part message.Therefore, the HLR front end processor being carried out the target of overloading control, is exactly by the access in the front end processor control information, so that the overload of certain part that the disposal ability of whole HLR system can system and descending.
With reference to figure 1, the present invention specifically realizes by following step: in step 1, the TMD of HLR front end processor receives the TC_INVOKE_REQ solicited message that transmits from TCAP, in step 2, obtain the occupation rate of the CPU of current front end processor, and obtain the flow control level of front end processor according to the occupation rate of this CPU.Described occupation rate according to CPU obtains the flow control level of front end processor, it is occupation rate according to this CPU, in the front end processor flow control meter that sets in advance, table look-up and obtain, the described front end processor flow control meter that sets in advance, be that the empirical value that test obtains according to the front end processor Bulk Call obtains, this table has suitable flow control level, and the best level of this flow control level is 6 grades, with reference to figure 3.In step 3, obtain the processing speed of MAP processor, and obtain the flow control level of this MAP processor according to the processing speed of MAP processor.Described processing speed according to the MAP processor obtains the flow control level of this MAP processor, is the processing speed according to the MAP processor, and tabling look-up in the flow control meter of the MAP processor that sets in advance obtains.The flow control meter of the described MAP processor that sets in advance, be to test the empirical value that obtains according to the Bulk Call of MAP processor to obtain, this table has suitable flow control level, and the optimum flow controlled stage of the flow control meter of the described MAP processor that sets in advance is 6 grades, with reference to figure 4.In obtaining the processing speed process of MAP processor, at first calculate HLR MAP processor and handle the time of a service primitive, promptly when sending a business request information, pick up counting, when receiving this service response message till, obtain time of a service primitive of HLR MAP processor processing; Can obtain HLR MAP processor then as follows and handle the average duration of a piece of news: a timer is set, for example duration is one minute, whenever the response message of returning, all write down the handling duration of this service primitive, processing messages duration summation addition with the front, divided by processing messages number summation, and then try to achieve the average duration that HLR MAP processor is handled a piece of news.In step 4, from the flow control level of the MAP processor of the flow control level of the HLR front end processor of above-mentioned steps 2 and above-mentioned steps 3, choose the maximum as the flow system flow controlled stage.In step 5, when the flow system flow controlled stage is the minimum flow controlled stage, then message all inserts, and changes step 10 and continues operation.In step 6, when the flow system flow controlled stage is the maximum flow controlled stage, then message is all refused, and changes step 9 and continues operation.In step 7, when the flow system flow controlled stage in the minimum flow controlled stage, in the time of between the maximum flow controlled stage, appoint and to get a random number and maximum flow level and deduct the flow system flow controlled stage and add 1 again and ask mould, promptly ask mould with maximum flow level-this flow system flow controlled stage+1.In step 8, judge whether this mould is zero, as be zero, change step 9 and continue operation, continue operation otherwise change step 10; If execution in step 9, the TC_INVOKE_REQ request message that the TMD of HLR front end processor refusal receives from TCAP, and send out TC_U_ABORT message to TCAP.If hold step row 10, the TMD of HLR front end processor sends the TC_INVOKE_REQ request message to HLR MAP processor, by the MMD continuation of HLR MAP processor this information is handled.
So far, the present invention controls the rate of abandoning of new information according to different flow control levels, to reduce information flow-rate, makes the overload in the cdma cellular communication system obtain imitating control, and makes system keep higher data disposal ability and performance.With reference to figure 5.Other message of different flow level that Fig. 5 has provided the embodiment of the invention inserts ratio, 1/5 1 of representing to abandon in 5 message among the figure, and 1 in 4 message is abandoned in 1/4 expression, and the like.Also promptly provided the rate of abandoning of every message, abandoned or send to HLRMAP specific to every message, by get a random number and traffic class, promptly the value of maximum flow level-flow control level+1 delivery decides.
Be example with the enroll in notifications message in the mobile management below, adopt the present invention to carry out HLR system overloading control, the present invention will be further described.
At first, the HLR front end processor receives the enroll in notifications request, receive this register request message that transmits from TCAP as the TMD of HLR front end processor after, at first obtain the occupation rate of the CPU of current front end processor, and obtain the flow control level of front end processor according to the occupation rate of this CPU.The occupation rate of supposing CPU is B1, and as the standard according to flow control rank table shown in Figure 3, then flow control rank is 1; Obtain the processing speed of MAP processor then, and obtain the flow control level of this MAP processor according to the processing speed of MAP processor.The processing speed of supposing the MAP processor is D2, and as the standard according to flow control rank table shown in Figure 4, then flow control rank is 3; From the flow control level of the flow control level of above-mentioned HLR front end processor and above-mentioned HLRMAP processor, choose the maximum, promptly 3 as the flow system flow controlled stage.Getting a random number and maximum flow level deducts the flow system flow controlled stage and adds 1 again and ask mould, promptly ask mould with 3, judge whether this mould is zero, as be zero, refuse the access of this message, and send out TC_U_ABORT message to TCAP, otherwise, send out TC_INVOKE_REQ message to HLR MAP, continue this information is handled by HLR MAP processor.
Usually, only under the situation of Bulk Call, just have very high flow control rank, just can begin to abandon message.
In a word, above-mentioned disclosed be a kind of method of in cdma cellular communication system HLR front end processor, carrying out system's overloading control, this method is to be in overload state when system, refuse the overloading control of the access realization system of a certain proportion of request message according to load class, because the technical scheme and the most preferred embodiment of this method are illustrated, therefore all within the scope of the present invention around any remodeling of said method.