CN103533577B - Vertical Handover judgement control method and system between a kind of heterogeneous wireless network - Google Patents

Abstract

The present invention provides Vertical Handover judgement control method and system between a kind of heterogeneous wireless network, method includes: S1, when the connection of mobile client Yu current network is unsatisfactory for the business need of mobile client, the base station of all heterogeneous networks that mobile client meets the business need of mobile client in scan list sends handover request；S2, this handover request is all sent to Vertical Handover controller by respective wireless senser by all base stations receiving handover request；S3, the historical channel resource distribution service condition information of each base station to be selected that Vertical Handover controller stores according to wireless senser calculates the blocking probability of each base station to be selected, and mobile client switching is connected to the base station that blocking probability is minimum.Vertical Handover judgement control method and system between a kind of heterogeneous wireless network that the present invention provides, Vertical Handover controller using the channel resource service condition information of each base station as the judgement foundation of mobile client Vertical Handover so that court verdict is more accurate.

Description

Vertical Handover judgement control method and system between a kind of heterogeneous wireless network

Technical field

The present invention relates to communication technical field, be specifically related to Vertical Handover judgement control method between a kind of heterogeneous wireless network And system.

Background technology

The fast development of mobile communication and evolution, cause the drastically expansion of heterogeneous network quantity.It is expected to not Coming, our wireless network environment will be flooded with the heterogeneous network of a large amount of different systems, specification and standard.And due to market Competition and complementary principle, these heterogeneous networks will progressively determine the market place of oneself, and merge completely at next generation network On the platform of network.Therefore heterogeneous network converged by become 3G, 4G and faced by further future network being had to one The trend of kind.In following wireless network environment, the seamless switching between heterogeneous network is requisite, is also that future network grinds A difficult point in studying carefully.

In order to solve this problem, sight is focused on the seamless mobility under heterogeneous network environment and supports research by people, Most important of which research concentrates on seamless switching.In heterogeneous network, switching is divided into horizontal handoff (HHO) and Vertical Handover (VHO) two kinds.Compared to horizontal handoff, Vertical Handover owing to occurring in the network of different structure, its switching mode and enforcement Increasingly complex, the most difficult.

The foundation of the judgement carrying out Vertical Handover in prior art is all and mobile terminal device communication obtains, according to movement The attribute of each network that terminal obtains makes decisions and how to switch, but the genus of each network that mobile device terminal is recognized Property Limited information, it is impossible to understand the loading condition at ordinary times of each network.

Summary of the invention

The present invention is directed to problem above, the existing network architecture is improved, it is proposed that between a kind of heterogeneous wireless network Vertical Handover judgement control method includes: step S1, when the current assessment connecting network is shown by mobile client, and described movement When the connection of user side and current network is unsatisfactory for the business need of described mobile client, described mobile client is to scan columns The base station of all heterogeneous networks meeting the business need of described mobile client in table sends handover request；

Step S2, all described base stations receiving described handover request all by respective wireless senser by described switching Request is sent to Vertical Handover controller；

Step S3, described wireless senser Real-time Collection also stores the channel resource allocation service condition of each described base station Information, described Vertical Handover controller sends the historical channel of each base station to be selected of handover request according to described mobile client Resource distribution service condition information calculates the blocking probability of each described base station to be selected, the switching of described mobile client is connected to The base station that blocking probability is minimum.

The present invention provide the first preferred embodiment in: mobile client described in described step S1 be mobile phone terminal or with or without Other mobile terminals of line access function, and described mobile terminal accessed a certain network under heterogeneous network environment, bag Include: LTE network, 3G network or WIFI network；

Described mobile client sends the base station of handover request and includes LTE base station, 3G network base station and wifi hotspot.

In the second preferred embodiment that the present invention provides: in described step S2, described mobile client is to currently connecting net In network and scan list, all-network judges whether that the business need meeting described mobile client is according to described network RSS value carries out judging, if the RSS value of network is less than the threshold value set, then judges that described network can not meet described shifting The business need of dynamic user side.

In the third preferred embodiment that the present invention provides: Vertical Handover controller described in described step S3 is according to each institute The historical channel resource stating base station to be selected distributes the method that service condition information calculates the blocking probability of each described base station to be selected Including:

Step S301, each described wireless senser collection and store each described base station each timing node T={t₁, t₂…t_zQuantity X of described mobile client of interior access base station i_i={ xⁱ ₁,xⁱ ₂…xⁱ _z-1And pick out the described movement of base station i Quantity Y of user side_i={ yⁱ ₁,yⁱ ₂…yⁱ _z-1}；

Z express time nodes；

Step S302, obtains t_zThe access of each described base station to be selected and the described mobile client that picks out in time period The meansigma methods of quantity: ${\mathrm{\λ}}_i\left(t_{z-1}\right)=(1/t_{z-1})\underset{k=1}{\overset{z-1}{\mathrm{\Σ}}}{x}_k$ With ${\mathrm{\μ}}_i\left(t_{z-1}\right)=(1/t_{z-1})\underset{k=1}{\overset{z-1}{\mathrm{\Σ}}}{y}_k;$

Described t_zTime period is manually set according to demand, and described wireless senser was fixed according to the time period of described setting Timing node carry out periodic data renewal, ask for the data that described meansigma methods uses be after recent renewal New data；

Step S303, distributes to Vertical Handover and Base station channel resources that to carry out abstract be the queuing model of a M/M/n/n, according to Queuing theory, the blocking probability calculating any one base station i is: $P_i={({\mathrm{\λ}}_i\left(t_{z-1}\right)/{\mathrm{\μ}}_i\left(t_{z-1}\right))}^n{(n!\underset{j=0}{\overset{n}{\mathrm{\Σ}}}{(({\mathrm{\λ}}_i\left(t_{z-1}\right)/{\mathrm{\μ}}_i\left(t_{z-1}\right))}^j/j!))}^{-1};$

N represents that base station maximum accommodates the number of channel；

The queuing model of M/M/n/n, for losing queuing model processed, represents that described mobile client access procedure is Poisson mistake Journey, the time interval arriving system is independent, and obedience parameter is the quantum condition entropy of λ, when n channel of base station is the most occupied Time, described mobile client is left away automatically.

In the 4th preferred embodiment that the present invention provides: described Vertical Handover controller calculates all described base stations to be selected Blocking probability after, if the handover blocking probability of former network is minimum, then keep the connection with described former network；If there being other The minimum network of blocking probability, described Vertical Handover controller sends to described mobile client and disconnects even with described former network The signaling connect and be connected with the network of described blocking probability minimum.

The 5th preferred embodiment that the present invention provides provides Vertical Handover judgement control system between a kind of heterogeneous wireless network, Including: the base station wireless senser (4) that connect communication corresponding with each described base station and with wireless senser each described (4) the Vertical Handover controller communicated with described base station；

Described base station includes LTE base station (2) and wifi hotspot (3)；When the connection of mobile client with current network is discontented with Foot described mobile client business need time, meet the base station of all heterogeneous networks of the business need of described mobile client Receiving the handover request that described mobile client sends, described handover request is passed through described respective wireless sensing by described base station Device (4) is sent to described Vertical Handover controller；

Described wireless senser (4) Real-time Collection that connect communication corresponding with each described base station also stores each described base The channel resource allocation service condition information stood；

Described Vertical Handover controller (5) receives what described base station was sent by respective described wireless senser (4) After described handover request, send the historical channel of each described base station to be selected of handover request according to described mobile client (1) Resource distribution service condition information calculates the blocking probability of each described base station to be selected, by described mobile client (1) switching even It is connected to the base station that blocking probability is minimum.

In the 6th preferred embodiment that the present invention provides: described mobile client (1) judges whether network meets business and want Seeking Truth carries out judging according to the RSS value of described network, if the RSS value of described network is less than the threshold value set, then judges Described network can not meet the business need of described mobile client.

In the 7th preferred embodiment that the present invention provides: described Vertical Handover controller (5) is according to base to be selected each described The method of the blocking probability that the historical channel resource distribution service condition information stood calculates each described base station to be selected includes:

Each time of each base station that described Vertical Handover controller (5) stores according to wireless senser each described (4) Node T={t₁,t₂…t_zQuantity X of described mobile client of interior access base station i_i={ xⁱ ₁,xⁱ ₂…xⁱ _z-1And pick out base station Quantity Y of the described mobile client of i_i={ yⁱ ₁,yⁱ ₂…yⁱ _z-1, obtain t_zThe access of each described base station to be selected in time period Meansigma methods with the quantity of the described mobile client picked out: ${\mathrm{\λ}}_i\left(t_{z-1}\right)=(1/t_{z-1})\underset{k=1}{\overset{z-1}{\mathrm{\Σ}}}{x}_k$ With ${\mathrm{\μ}}_i\left(t_{z-1}\right)=(1/t_{z-1})\underset{k=1}{\overset{z-1}{\mathrm{\Σ}}}{y}_k;$

Wherein, z express time nodes, described t_zTime period is manually set according to demand, described wireless senser (4) root Periodic data renewal, described Vertical Handover controller (5) is carried out according to the time period node at a fixed time of described setting The data that averaged uses are the latest data after recent renewal；

Vertical Handover and Base station channel resources are distributed that to carry out abstract be the row of a M/M/n/n by described Vertical Handover controller (5) Team's model, according to queuing theory, the blocking probability calculating any one base station i is: $P_i={({\mathrm{\λ}}_i\left(t_{z-1}\right)/{\mathrm{\μ}}_i\left(t_{z-1}\right))}^n{(n!\underset{j=0}{\overset{n}{\mathrm{\Σ}}}{(({\mathrm{\λ}}_i\left(t_{z-1}\right)/{\mathrm{\μ}}_i\left(t_{z-1}\right))}^j/j!))}^{-1};$

Wherein, n represents that base station maximum accommodates the number of channel；

The queuing model of M/M/n/n, for losing queuing model processed, represents that described mobile client access procedure is Poisson mistake Journey, the time interval arriving system is independent, and obedience parameter is the quantum condition entropy of λ, when n channel all quilts of described base station When taking, described mobile client is left away automatically.

In the 8th preferred embodiment that the present invention provides: described Vertical Handover controller (5) calculates all described to be selected After the blocking probability of base station, if the handover blocking probability of former network is minimum, then keep the connection with former network；If there being other The minimum network of blocking probability, described Vertical Handover controller (5) sends and described former network to described mobile client (1) The signaling disconnected and be connected with the network of described blocking probability minimum.

Vertical Handover judgement control method and the beneficial effect bag of system between a kind of heterogeneous wireless network that the present invention provides Include:

1, Vertical Handover judgement control method and system between a kind of heterogeneous wireless network that the present invention provides, to prevailing network Framework improves, and arranges the Vertical Handover controller all communicated with base station and mobile client, and each base station is by wireless biography The channel resource service condition information of base station is sent to Vertical Handover controller by sensor, as mobile client Vertical Handover Judgement foundation so that court verdict is more accurate.Simultaneously as be to be carried out unifying judgement, by right by Vertical Handover controller The programmable transformation of Vertical Handover controller decision algorithm so that network can change vertically according to different requirement of manager The foundation of switch decision, adds the control power to network integrated environment and operability, can more preferable distributing radio resource, carry The load balancing of high network.

The historical channel resource distribution service condition information of the wireless senser storage that 2, Vertical Handover controller uses Time period can be manually set according to demand, if needing to gather mass data to take accurate mean values, can set A longer time period, such as one month, if it is considered that the particularity of period, need the history of a nearer time range Data, can set a shorter time period, and such as one hour, arranging flexibly of the time period of historical data made structure The most accurate.

Accompanying drawing explanation

It is illustrated in figure 1 the flow process of Vertical Handover judgement control method between a kind of heterogeneous wireless network that the present invention provides Figure；

It is illustrated in figure 2 the structure of Vertical Handover judgement control system between a kind of heterogeneous wireless network that the present invention provides Figure.

Detailed description of the invention

Below according to accompanying drawing, the detailed description of the invention of the present invention is described in further detail.

The present invention provides Vertical Handover judgement control method between a kind of heterogeneous wireless network, its flow chart as it is shown in figure 1, by Fig. 1 understands, and the method includes:

Step S1, when the current assessment connecting network is shown by mobile client, this mobile client and current network When connecting the business need being unsatisfactory for mobile client, mobile client meets the business of mobile client in scan list to be wanted The base station of all heterogeneous networks asked sends handover request.

Step S2, this handover request is all sent to by all base stations receiving handover request by respective wireless senser Vertical Handover controller.

Step S3, wireless senser Real-time Collection also stores the channel resource allocation service condition information of each base station, hangs down Vertical cut changer controller sends the historical channel resource distribution of each base station to be selected of handover request and uses feelings according to mobile client Condition information calculates the blocking probability of each base station to be selected, and mobile client switching is connected to the base station that blocking probability is minimum.

Further, in step S1, mobile client is mobile phone terminal or other mobile terminals having wireless access function, and And this mobile terminal has accessed a certain network under heterogeneous network environment, such as LTE network, 3G network or WIFI network etc., move Dynamic user side sends the base station of handover request and includes LTE base station, 3G network base station and wifi hotspot etc..

In step S2, all-network in current connection network and scan list is judged whether to meet shifting by mobile client The business need of dynamic user side is the RSS(received signal strength according to network, accepts signal intensity) value enters Row judges, if the RSS value of network is less than the threshold value set, then judges that this network can not meet the business of mobile client Requirement.

Vertical Handover controller decision algorithm can be according to the different foundations requiring to change Vertical Handover judgement of manager Carry out programmable transformation, add the control power to network integrated environment and operability, Vertical Handover controller in step S3 Historical channel resource distribution service condition information according to each base station to be selected calculates the side of the blocking probability of each base station to be selected One embodiment of method includes:

Step S301, each wireless senser collection and store each base station each timing node T={t₁,t₂…t_zIn } Quantity X of the mobile client of access base station i_i={ xⁱ ₁,xⁱ ₂…xⁱ _z-1And pick out quantity Y of mobile client of base station i_i= {yⁱ ₁,yⁱ ₂…yⁱ _z-1, z express time nodes.

Step S302, obtains t_zThe access of each base station to be selected and the quantity of mobile client that picks out is flat in time period Average: ${\mathrm{\λ}}_i\left(t_{z-1}\right)=(1/t_{z-1})\underset{k=1}{\overset{z-1}{\mathrm{\Σ}}}{x}_k$ With ${\mathrm{\μ}}_i\left(t_{z-1}\right)=(1/t_{z-1})\underset{k=1}{\overset{z-1}{\mathrm{\Σ}}}{y}_k.$

Wherein, this t_zTime period can be manually set according to demand, takes accurately if needing to gather mass data Mean values, can set a longer time period, such as one month, if it is considered that the particularity of period, need one relatively The historical data of near time range, can set a shorter time period, such as one hour.Wireless senser is according to being somebody's turn to do The time period node at a fixed time set carries out periodic data renewal, the number that in step S302, averaged uses According to for the latest data after recent renewal.

Step S303, plans the behavior of each base station by queueing theory, distributes Vertical Handover and Base station channel resources and carries out Abstract is the queuing model of a M/M/n/n, and according to queuing theory, the blocking probability calculating any one base station i is: $P_i={({\mathrm{\λ}}_i\left(t_{z-1}\right)/{\mathrm{\μ}}_i\left(t_{z-1}\right))}^n{(n!\underset{j=0}{\overset{n}{\mathrm{\Σ}}}{(({\mathrm{\λ}}_i\left(t_{z-1}\right)/{\mathrm{\μ}}_i\left(t_{z-1}\right))}^j/j!))}^{-1}.$

Wherein n represents that base station maximum accommodates the number of channel.The queuing model of M/M/n/n, for losing queuing model processed, represents and moves Employing family end access procedure is Poisson process, and the time interval arriving system is independent, and obedience parameter is the quantum condition entropy of λ, When n channel of base station whole occupied time, mobile client is left away automatically.

After Vertical Handover controller calculates the blocking probability of all base stations to be selected, if the handover blocking probability of former network Minimum, then keep the connection with former network；If there being the network that other blocking probability is minimum, this Vertical Handover controller is to this Mobile client sends the signaling disconnecting with former network and being connected with the network of blocking probability minimum.

The present invention also provides for Vertical Handover judgement control system between a kind of heterogeneous wireless network, its structure chart as in figure 2 it is shown, As shown in Figure 2, this system includes: the base station wireless senser (4) and with each wireless that connect communication corresponding with each base station The Vertical Handover controller that sensor (4) communicates with base station.

Base station includes LTE base station (2) and wifi hotspot (3) etc., when mobile client (UE, User Equipment) with work as When the connection of front network is unsatisfactory for the business need of mobile client, meet all isomeries of the business need of this mobile client The base station of network receives the handover request that this mobile client sends, base station by this request by respective wireless senser (4) It is sent to Vertical Handover controller.

The channel resource that connect wireless senser (4) Real-time Collection that communicate and store each base station corresponding with each base station Distribution service condition information.

After Vertical Handover controller (5) receives the handover request that base station is sent by respective wireless senser (4), root The historical channel resource distribution service condition information of each base station to be selected sending handover request according to this mobile client (1) calculates The blocking probability of each base station to be selected, is connected to, by this mobile client (1) switching, the base station that blocking probability is minimum.

Prevailing network framework is improved, the Vertical Handover controller all communicated with base station and mobile client is set, The channel resource service condition information of base station is sent to Vertical Handover controller by each base station by wireless senser, as shifting The judgement foundation of dynamic user side Vertical Handover so that court verdict is more accurate.Simultaneously as be to be entered by Vertical Handover controller The unified judgement of row, by transforming the programmable of Vertical Handover controller decision algorithm so that network can be according to manager The different foundations requiring to change Vertical Handover judgement, add the control power to network integrated environment and operability, Ke Yigeng Good distributing radio resource, improves the load balancing of network.

Further, mobile client (1) judges whether network meets business need is that the RSS value according to network is sentenced Break, if the RSS value of network less than set threshold value, then judge this network can not meet mobile client business want Ask.

Vertical Handover controller (5) distributes service condition information according to the historical channel resource of each base station to be selected and calculates each The method of the blocking probability of individual base station to be selected includes:

Each base station each timing node T=that Vertical Handover controller (5) stores according to each wireless senser (4) {t₁,t₂…t_zQuantity X of mobile client of interior access base station i_i={ xⁱ ₁,xⁱ ₂…xⁱ _z-1And pick out the mobile subscriber of base station i Quantity Y of end_i={ yⁱ ₁,yⁱ ₂…yⁱ _z-1, z express time nodes, obtain t_zIn time period each base station to be selected access and The meansigma methods of the quantity of the mobile client picked out: ${\mathrm{\λ}}_i\left(t_{z-1}\right)=(1/t_{z-1})\underset{k=1}{\overset{z-1}{\mathrm{\Σ}}}{x}_k$ With ${\mathrm{\μ}}_i\left(t_{z-1}\right)=(1/t_{z-1})\underset{k=1}{\overset{z-1}{\mathrm{\Σ}}}{y}_k.$

Wherein, this t_zTime period can be manually set according to demand, takes accurately if needing to gather mass data Mean values, can set a longer time period, such as one month, if it is considered that the particularity of period, need one relatively The historical data of near time range, can set a shorter time period, such as one hour.Wireless senser (4) root Carrying out periodic data renewal according to the time period node at a fixed time of this setting, Vertical Handover controller (5) is asked for putting down The data that average uses are the latest data after recent renewal.

Vertical Handover and Base station channel resources are distributed that to carry out abstract be the queuing mould of a M/M/n/n by Vertical Handover controller (5) Type, according to queuing theory, the blocking probability calculating any one base station i is: $P_i={({\mathrm{\λ}}_i\left(t_{z-1}\right)/{\mathrm{\μ}}_i\left(t_{z-1}\right))}^n{(n!\underset{j=0}{\overset{n}{\mathrm{\Σ}}}{(({\mathrm{\λ}}_i\left(t_{z-1}\right)/{\mathrm{\μ}}_i\left(t_{z-1}\right))}^j/j!))}^{-1}.$

Wherein n represents that base station maximum accommodates the number of channel.The queuing model of M/M/n/n, for losing queuing model processed, represents and moves Employing family end access procedure is Poisson process, and the time interval arriving system is independent, and obedience parameter is the quantum condition entropy of λ, When n channel of base station whole occupied time, mobile client is left away automatically.

After Vertical Handover controller (5) calculates the blocking probability of all base stations to be selected, if the handover blocking of former network Probability is minimum, then keep the connection with former network；If having the network that other blocking probability is minimum, this Vertical Handover controller (5) signaling disconnecting with former network and being connected with the network of blocking probability minimum is sent to this mobile client (1).

Finally should be noted that: above example is only in order to illustrate that technical scheme is not intended to limit, to the greatest extent The present invention has been described in detail by pipe with reference to above-described embodiment, and those of ordinary skill in the field are it is understood that still The detailed description of the invention of the present invention can be modified or equivalent, and any without departing from spirit and scope of the invention Amendment or equivalent, it all should be contained in the middle of scope of the presently claimed invention.

Claims (8)

1. Vertical Handover judgement control method between a heterogeneous wireless network, it is characterised in that described method includes:

Step S1, when the current assessment connecting network is shown by mobile client, described mobile client and the company of current network When connecing the business need being unsatisfactory for described mobile client, described mobile client meets described mobile subscriber in scan list The base station of all heterogeneous networks of the business need of end sends handover request；

Step S2, all described base stations receiving described handover request all by respective wireless senser by described handover request It is sent to Vertical Handover controller；

Step S3, described wireless senser Real-time Collection and store each described base station channel resource allocation service condition letter Breath, described Vertical Handover controller sends the historical channel money of each base station to be selected of handover request according to described mobile client Source distribution service condition information calculates the blocking probability of each described base station to be selected, and the switching of described mobile client is connected to resistance The base station that plug probability is minimum；

Vertical Handover controller described in described step S3 distributes use according to the historical channel resource of base station to be selected each described The method of the blocking probability that situation information calculates each described base station to be selected includes:

Step S301, each described wireless senser collection and store each described base station each timing node T={t₁,t₂… t_zQuantity X of described mobile client of interior access base station i_i={ xⁱ ₁,xⁱ ₂…xⁱ _z-1And pick out the described mobile of base station i and use Quantity Y of family end_i={ yⁱ ₁,yⁱ ₂…yⁱ _z-1}；

Z express time nodes；

Step S302, obtains t_zThe access of each described base station to be selected and the quantity of described mobile client that picks out in time period Meansigma methods:With

Described t_zTime period is manually set according to demand, described wireless senser according to time period of described setting when fixing Intermediate node carries out periodic data renewal, and asking for the data that described meansigma methods uses is the up-to-date number after recent renewal According to；

Step S303, distributes to Vertical Handover and Base station channel resources that to carry out abstract be the queuing model of a M/M/n/n, according to row Team theory, the blocking probability calculating any one base station i is:

N represents that base station maximum accommodates the number of channel；

The queuing model of M/M/n/n, for losing queuing model processed, represents that described mobile client access procedure is Poisson process, arrives The time interval reaching system is independent, and to obey parameter be the quantum condition entropy of λ, when n channel of base station whole occupied time, institute State mobile client automatically to leave away.

2. the method for claim 1, it is characterised in that mobile client described in described step S1 is mobile phone terminal or has Other mobile terminals of wireless access function, and described mobile terminal accessed a certain network under heterogeneous network environment, Including: LTE network, 3G network or WIFI network；

Described mobile client sends the base station of handover request and includes LTE base station, 3G network base station and wifi hotspot.

3. the method for claim 1, it is characterised in that in described step S2, described mobile client connects current In network and scan list, all-network judges whether that the business need meeting described mobile client is according to described network RSS value carry out judging, if the RSS value of network is less than the threshold value set, then judge that described network can not meet described The business need of mobile client.

4. the method for claim 1, it is characterised in that described Vertical Handover controller calculates all described bases to be selected After the blocking probability stood, if the handover blocking probability of former network is minimum, then keep the connection with described former network；If there being it The network that his blocking probability is minimum, described Vertical Handover controller sends to described mobile client and disconnects with described former network The signaling connected and be connected with the network of described blocking probability minimum.

5. between a heterogeneous wireless network, vertical judgement controls switched system, it is characterised in that described system includes: base station and Each described base station correspondence connect communication wireless senser (4) and with wireless senser each described (4) and described base station The Vertical Handover controller of communication；

Described base station includes LTE base station (2) and wifi hotspot (3)；When the connection of mobile client Yu current network is unsatisfactory for institute When stating the business need of mobile client, the base station of all heterogeneous networks meeting the business need of described mobile client receives The handover request that described mobile client sends, described handover request is sent out by described base station by respective wireless senser (4) Give described Vertical Handover controller；

Described wireless senser (4) Real-time Collection that connect communication corresponding with each described base station also stores each described base station Channel resource allocation service condition information；

Described Vertical Handover controller (5) receive described base station by respective described wireless senser (4) send described After handover request, send the historical channel resource distribution of each base station to be selected of handover request according to described mobile client (1) Service condition information calculates the blocking probability of each described base station to be selected, is connected to block by described mobile client (1) switching The base station that probability is minimum.

6. system as claimed in claim 5, it is characterised in that described mobile client (1) judges whether network meets business Requirement is that the RSS value according to described network carries out judging, if the RSS value of described network is less than the threshold value set, then sentences Disconnected described network can not meet the business need of described mobile client.

7. system as claimed in claim 5, it is characterised in that described Vertical Handover controller (5) is according to be selected each described The method of the blocking probability that the historical channel resource distribution service condition information of base station calculates each described base station to be selected includes:

Each base station each timing node T that described Vertical Handover controller (5) stores according to wireless senser each described (4) ={ t₁,t₂…t_zQuantity X of described mobile client of interior access base station i_i={ xⁱ ₁,xⁱ ₂…xⁱ _z-1And pick out the institute of base station i State quantity Y of mobile client_i={ yⁱ ₁,yⁱ ₂…yⁱ _z-1, obtain t_zThe access of each described base station to be selected and connecing in time period The meansigma methods of the quantity of the described mobile client gone out:With

Wherein, z express time nodes, described t_zTime period is manually set according to demand, and described wireless senser (4) is according to institute The time period node at a fixed time stating setting carries out periodic data renewal, and described Vertical Handover controller (5) is asked for The data that meansigma methods uses are the latest data after recent renewal；

Vertical Handover and Base station channel resources are distributed that to carry out abstract be the queuing model of a M/M/n/n by described Vertical Handover controller (5), According to queuing theory, the blocking probability calculating any one base station i is:

Wherein, n represents that base station maximum accommodates the number of channel；

The queuing model of M/M/n/n, for losing queuing model processed, represents that described mobile client access procedure is Poisson process, arrives The time interval reaching system is independent, and obedience parameter is the quantum condition entropy of λ, when n channel of described base station is the most occupied Time, described mobile client is left away automatically.

8. system as claimed in claim 5, it is characterised in that described Vertical Handover controller (5) calculate all described in treat After selecting the blocking probability of base station, if the handover blocking probability of former network is minimum, then keep the connection with former network；If there being it The network that his blocking probability is minimum, described Vertical Handover controller (5) sends and described former net to described mobile client (1) The signaling that network disconnects and the network minimum with described blocking probability is connected.