WO2008034877A1

WO2008034877A1 - Method and apparatus for selecting a mobile communication network

Info

Publication number: WO2008034877A1
Application number: PCT/EP2007/059964
Authority: WO
Inventors: Xue Jun Cai
Original assignee: Siemens Aktiengesellschaft
Priority date: 2006-09-20
Filing date: 2007-09-20
Publication date: 2008-03-27
Also published as: CN101150795A

Abstract

The present invention discloses a method for selecting a mobile communication network, comprising monitoring in each of the available networks; a network parameter of concern to a user and a parameter relevant to said network parameter, wherein if said network parameter and/or said relevant parameter are/is changed, a function value of each of the available networks is obtained on the basis of said network parameter and said relevant parameter, and the available network with the maximum function value is selected as a target network. The present invention further discloses an apparatus for selecting a mobile communication network. According to the present invention, the function value of each of the available networks is obtained by using a dynamic network parameter, so as to improve the efficiency of the network selection, and to increase the probability that the network selected by a mobile terminal meets the needs of a user.

Description

Method and Apparatus for Selecting a Mobile Communication Network

Technical Field

The present invention relates to the technical field of mobile communications, and particularly to a method and apparatus for selecting a mobile communication network.

Background Art

Recently, fast developments of wireless mobile communications have facilitated the creation of a large number of wireless mobile communication technologies. Usually, networks formed by using different technological mechanisms would have some overlapping areas, as shown in Fig. 1. Fig. 1 includes networks of various mechanisms, such as, Global System for Mobile Communications

(GSM) /General Packet Radio Service (GPRS) network, Wireless Local Area Network (WLAN) , WiMAX network, Code Division Multiple Access

(CDMA) , 3G network, and IP Based Core network, however, these networks with different mechanisms do not have clear cut divisions between them, and instead they have overlapping areas . The benefits of the co-existence of the networks with various mechanisms are that a variety of services can be supplied to users, such as, a WLAN can provide high-speed network access at specific positions, such as hot spots, while a Cellular Mobile Network can provide extensive network access but its bandwidth is narrow and the costs are high.

When a user with a multi-mode mobile terminal (MT) is moving across networks with different mechanisms, an important problem for the user is how to select a network for use, due to each network' s unique properties. With reference to Fig. 1, it is assumed that there are two networks available to the user for selection, one is a WLAN network, and the other is a WiMAX network. The cost of using the WLAN network is low, while a bigger bandwidth is available with the WiMAX network. How does the user select a network?

One basic solution is to select a network according to the network' s signal intensity and the other according to network parameters; although this solution is simple, neither the requirements for network factors, such as, costs, bandwidth, security and so on, nor the natural character of each network is considered.

In order to solve the problems in the above-mentioned method, a method for selecting the network based on the user requirements and network characters is proposed. When using this method, a user sets weighted values according to his own requirements to the network parameters concerned, which can also be referred to by forming a user strategy. The user's level of concern to various parameters in the network is presented in the user strategy. If, as shown in Fig. 2, assuming a mobile terminal is located within two overlapping networks, one is a WLAN network, and the other a CDMA/1X network, some of the inherent network parameters of the two are shown in Table 1.

Table 1

When MT selects a network, on the basis of a predetermined functional

N relationship Q = ∑W_t-F_t , a Q value for each network will be

calculated respectively and the network with the maximum Q is selected as the current network (CN) .

In this functional relationship, F₁ is the network parameter that the user is concerns with, W₁ is the weighted value set by the user for the network parameter concerned, and N is the total number of the network parameters .

Assuming the bandwidth provided by the network is the user's principal concern, the weighted value W_b for the network parameter "bandwidth" is set relatively high, such as 0.8, while the network' s service charge and the network security are less of a concerned for the user, the weighted value W_c for the network parameter "cost" is set relatively low, such as 0.1, and the weighted value W₃ for the network parameter "security" is also set relatively low, such as 0.1.

When the network is a WLAN, £ = 0.1x2 +0.8x11+0.1x3 = 9.3 ; when the

network is CDMA/1X, £ = 0.1x1 +0.8x0.36+0.1x5 = 0.888 . After the Q values of the WLAN network and the CDMA/1X network are calculated, the MT will select the WLAN network with the bigger Q value as the target network.

In the above-described method, the unit of each network parameter is different, for example, the unit of the "cost" is "Yuan/hour", and the unit of the "bandwidth" is "Mbit/s", while the security level has no unit . Although in view of mathematics, weighting and summing up the data with different units are meaningless, from the view point of the strategy for selecting networks, the method provides a useful reference. Although the use of the above method as a strategy for selecting networks has taken both the user's requirements and the natural characters of the networks into consideration, when calculating the Q value for each available network in the above method, the network parameter F₁ of each available network uses a fixed value. During an actual operation, many network parameters will change dynamically due to the effects of practical factors, for example, the bandwidth actually enjoyed by a MT from an available network will be affected by the number of users in that network, and the security levels provided by the available networks will also be changed according to different application services. Moreover, at different times during an operation, the application programs running in the MT are different, and the requirements for the network parameters by these applications are different too. When the network parameters of each available network are changed following the changes of practical factors, if MT still uses the fixed network parameters for each available network, the effects of the network selection will be reduced, and even leading to the case that the selected network is far away from meeting the user's needs.

Summary of the Invention

In view of what is described above, the solution by the present invention to the technical problem is to provide a method and an apparatus for selecting a mobile communication network, and compared to the prior art, when using this method and apparatus, the results in selecting networks can be improved, the probability for the network selected by the MT to meet the user' s needs is increased.

For this purpose, the technical solution provided by the present invention is as follows:

a method for selecting a mobile communication network, comprising:

monitoring a network parameter of concern to a user and a parameter relevant to said network parameter in each of available networks, wherein if said network parameter and/or said relevant parameter are/is changed, a function value of each of the available networks is obtained on the basis of said network parameter and said relevant parameter, and the available network with the maximum function value is selected as a target network.

Wherein, when said relevant parameter is a weighted value of said network parameter, the function value of the available networks is obtained by the following steps:

calculating W₁-V₁ to obtain the weighted value of the network parameter; and

N calculating J = ^W₁-V₁ to obtain the function value of the available

networks, wherein, f is the function value of the available networks, V₁ is the network parameter concerned by the user, W₁ is the weighted value of V₁, and N is the total number of the network parameter (s) .

Wherein, when said relevant parameter is the weighted value of the network parameter and an expected value of the network parameter, the function value of the available networks is obtained by the following steps: calculating — V*- to obtain the user's satisfaction level with the

network parameter;

V calculating W_t-{—-) to obtain the weighted value of said

^E, satisfaction level; and

calculating f to obtain the function value of the

available networks,

wherein, f is the function value of the available networks, V₁ is the network parameter of concern to the user, W₁ is the weighted value of V₁, E₁ is the expected value of V₁, and N is the total number of the network parameter (s) .

Wherein, said expected value E₁ of said network parameter is set by the user or by the mobile terminal according to a need for at least one application service.

Wherein, when at least one application service is performed by the mobile terminal, the expected value of the network parameter is set by the mobile terminal according to the following steps :

calculating S_j -E_y to obtain the weighted value of a need value of the application service for the network parameter V₁; and M calculating E₁ = ^~∑S -E to obtain and set the expected value E₁ of

the network parameter V₁,

wherein, E₁₃ is the need value of different application services for the network parameter V₁, S₃ is the weighted value corresponding to E_1J, and M is the total number of the application service (s) .

Wherein, when the weighted value W₁ is set directly by the user, W₁ is set by the following conditions:

N

O≤røζ≤l, and ^W₁=X; wherein, N is the total number of the network

parameter (s) .

Wherein when the weighted value W₁ is not a coefficient set directly by the user, the weighted value is set by the following steps: setting a coefficient W₁ for the network parameter by the user;

N calculating ∑w, to obtain the sum of all the W₁; and ι=l

calculating W₁ = to obtain and set the weighted value W₁ of the

network parameter V₁, wherein, N is the total number of the network parameter (s) .

Wherein, when there are more than one available networks with the maximum function value, if the network in which the mobile terminal is currently located has the maximum function value, then the network in which the mobile terminal is currently located is selected as the target network, otherwise, one of the available networks with the maximum function value is selected randomly as the target network, or one of the available networks with the maximum function value is selected based on a predetermined condition.

An apparatus for selecting a mobile communication network, comprising :

a monitoring unit for monitoring a network parameter of concern to the user and a parameter relevant to said network parameter in each of the available networks;

a determining unit for determining whether relevant monitored value obtained by the monitoring unit is changed;

a function value acquiring unit for receiving information from the determining unit, and for obtaining the function value of each of the available networks according to the monitored value if the relevant monitored value is being changed, ; and

a network selecting unit for receiving the function value obtained by the function value acquiring unit, and for selecting the available network with the maximum function value as a target network.

Wherein, when said relevant parameters are weighted values of the network parameters, said function value acquiring unit comprises:

a multiplying unit for calculating W₁-V₁ to obtain the weighted value of the network parameter; and

N an accumulating unit for calculating Z = ^₁W₁-V₁ to obtain the

function value of the available network,

wherein, f is the function value of the available network, V₁ is the network parameter concerned by the user, W₁ is the weighted value of V₁, and N is the total number of the network parameter (s) .

Wherein, when said relevant parameter is a weighted value of said network parameter and an expected value of the network parameter, said function value acquiring unit comprises: V a dividing unit for calculating —*- to obtain a satisfaction level

of the user with the network parameter;

V a multiplying unit for calculating W • (—'-) to obtain a weighted

E₁ value of said satisfaction level; and

A_-1 γ an accumulating unit for calculating f = /_W₁-(—'-) to obtain the

_*=i ^E, function value of the available network,

wherein, f is the function value of the available network, V₁ is the network parameter concerned by the user, W₁ is the weighted value of V₁, E₁ is the expected value of V₁, and N is the total number of the network parameter (s) .

Wherein, said apparatus further comprises an expected value setting unit for setting the expected value of said network parameter.

Wherein, the expected value of said network parameter is set by the user via the expected value setting unit, or by the mobile terminal via the expected value setting unit according to a need for at least one application service.

Wherein, when at least one application service is performed by the mobile terminal, said expected value setting unit comprises: a need value weighting unit for calculating S_j -E_1J to obtain a weighted value of the need value of the application service for the network parameter V₁; and

M a weighted value accumulating unit for calculating E₁=^S_j-E_1J to

_J=I obtain and set the expected value E₁ of the network parameter V₁, wherein, E₁₃ is the need value of different application services for the network parameter V₁, S₃ is the weighted value corresponding to E₁₃, and M is the total number of the application service (s) . Wherein, when the weighted value W₁ is not a coefficient set directly by the user, said apparatus further comprises:

N a summing unit for calculating ∑w_; for the coefficient W₁ set by

the user to obtain the sum of all the W₁; and

a weighted value acquiring unit for calculating W₁ = to obtain

and set the weighted value W₁ of the network parameter V₁; wherein, N is the total number of the network parameter (s) .

It can be seen here that when the method and apparatus for selecting the mobile network according to the present invention are adopted, it is necessary to monitor the network parameters of concern to the user and parameters relevant to said network parameters in each available network, if said network parameters and/or said relevant parameters are changed, the function value of each available network are obtained according to said network parameters and said relevant parameters, and the available network with the maximum function value is selected as a target network. Compared with the prior art, in the present invention a target network is selected on the basis of the dynamic network parameters, so as to improve the results of the network selection, and to increase the probability for the network selected by the MT to meet the user needs. In the present invention, the expected values for the relevant network parameters can be set according to the needs for various application services, and the users' level of satisfaction with the network parameters concerned are taken into consideration. Therefore, it not only achieves the selection of the target network based on the dynamic network parameters, but also solves the problem of the inconsistent units of the network parameters, therefore it represents the users' level of satisfaction with the network parameters concerned, and also meets the needs for different application services to the network parameters. Description of the accompanying drawings

Fig.l is an illustrative diagram of various networks overlapping one another;

Fig.2 is an illustrative diagram of a mobile terminal located in overlapping networks;

Fig.3 is a flowchart of the method according to an embodiment 1 of the present invention;

Fig.4 is a flowchart of the method according to an embodiment 2 of the present invention;

Fig.5 is a first illustrative diagram of the apparatus according to the present invention;

Fig.6 is an illustrative diagram of a function value acquiring unit in the apparatus according to the present invention;

Fig.7 is a second illustrative diagram of the apparatus according to the present invention;

Fig.8 is an illustrative diagram of an expected value setting unit in the apparatus according to the present invention; and

Fig.9 is a third illustrative diagram of the apparatus according to the present invention.

Embodiments

The core concept of the present invention is to monitor network parameters concerned by a user and parameters relevant to said network parameters in each available network, and to select a target network based on the dynamically changing network parameters.

Hereinafter, the method is further described with reference to an embodiment 1, and Fig. 3 is the flowchart of the embodiment 1.

Assuming a multi-mode MT is located in a current network, in the step 301, the MT monitors the network parameters of concern to the user in the available networks. In the step 302, the MT monitors the user strategy, i.e. monitors the weighted value of each network parameter set by the user. Here, the monitoring of the network parameters and the user strategy can be performed periodically or non-periodically, but for the sake of clarity, the monitoring of the network parameters and the user strategy can be performed periodically. Therein, not only the monitoring of the network parameters is performed to the available networks, but also if a new network becomes available to the MT, the network parameters of the new available network are monitored by the MT.

In the step 303, when each available network is affected by practical factors, if the network parameters monitored by the MT in each available network are changed, the network parameter is updated by the MT in the step 304, otherwise, the monitoring continues.

In the step 305, if the weighted value of a network parameter is reset by the user, i.e. the user strategy is changed, the user strategy information, i.e. the weighted value of the relevant network parameter, is updated by the MT in the step 306; otherwise, the monitoring continues.

In the step 307, if neither the network parameters monitored by the MT nor the corresponding user strategy are changed or updated, then the step 310 is performed and the network selection is not carried out; otherwise, in the step 308, the function value of each available network is re-calculated by the MT on the basis of the network parameters in the available network and the corresponding user strategy according to the following functional relationship:

wherein, f is the function value of the available networks, V₁ is the network parameter of concern to the user, W₁ is the weighted value of V₁ set by the user, and N is the total number of the network parameter V₁.

After obtaining the function value of each available network, the available network with the maximum function value is selected, in the step 309, as the target network.

Hereinafter, the method of the embodiment 1 is described in more detail with reference to Fig. 2. Assuming the MT is located in two available networks at the same time, one is a WLAN network; the other is a CDMA/1X network. It is assumed that the network parameters and the user strategy saved in the MT are those shown in Table 2. It can be seen in Table 2 that the network parameters of concern to the user are "cost", "bandwidth", and "security level", and the user has set the corresponding weighted values of the concerned network parameters to 0.1, 0.7, and 0.2 respectively. It can be seen that the bandwidth that can be provided by the network is of most concern to the user, the second one is the security level of the network, and the last one is the cost. As to these 3 network parameters of concern to the user, the "cost" of 2 Yuan/hour, the "bandwidth" of 200 Kbit/s, and the security level of 5 are provided by the WLAN network to the MT, while the cost of 1 Yuan/hour, the bandwidth of 300 Kbit/s, and the security level of 3 are provided by CDMA/ IX network to the MT.

Table 2

After calculating, the function value of the WLAN network obtained is: f_w =0.1x(l/2) +0.7x200+0.2x5 = 141.05 ; and the function value of

CDMA/1X network is: f_c =0.1x1 + 0.7x210 + 0.2x3 = 147.7 , so the CDMA/1X network is selected by the MT.

When using the method discussed above, as to the network parameter "cost", at the time of function calculation it is not using its actually monitored value as the network parameter, and instead it is the reciprocal of the actually monitored value that is used as the network parameter. This is because when the user is concerned more about a certain parameter, a higher weighted value will be set for this parameter, but the user actually wants to reduce such a parameter, for example, the parameters such as the "cost" or "power consumption". When the user is concerned about "cost" or "power consumption" and sets higher weighted values for them, the user usually intends to get a lower cost or power consumption, so for these kind of network parameters, only when the reciprocals of the actually monitored values are used as the network parameters in the function computation, they will really meet the user's needs.

The network parameters concerned by the user and the corresponding user strategy are monitored by the MT. If the network parameter "bandwidth" in the WLAN network is changed, the MT updates the corresponding parameter stored in it, and the updated network parameters and the corresponding user strategy are shown in Table 3.

Table 3

When any change of the network parameters is monitored by the MT, the function values for the two networks are re-calculated, then, f_w =0.1x(l/2)+0.7x210+0.2x5 = 148.05 ; f_c =0.1x1 + 0.7x210 + 0.2x3 = 147.7 , so the WLAN network is selected by the MT as the target network. If the user strategy is changed, the MT will update the user strategy stored in it, and the updated network parameters and the corresponding user strategy are shown in Table 4.

Table 4

level

Weighted 0.1 0.1 0.8 value

WLAN 2 Yuan/hour 200 Kbit/s 5

CDMA/ IX 1 Yuan/hour 210 Kbit/s 3

When the change of the user strategy is monitored by the MT, the function values for two networks are re-calculated, then

/_(F=0.1x(l/2)+0.1x200+0.8x5 = 24.05; f_c =0.1x1+0.1x210+0.8x3 = 23.5 , so the

MT will select the WLAN network as the target network.

It can be seen that, in the embodiment 1, the network parameters of concern to the user and the corresponding user strategy are monitored by the MT, and the target network is selected dynamically on the basis of the changes in the network parameters and the corresponding user strategy, so that the result of the network selection is improved and the probability that the network selected by the mobile terminal meets the user' s need is increased. However, the unit of each network parameter in this method is different and the user' s satisfaction level to the network parameters is not represented. For solving the above problem, the present invention further proposes a method for selecting a mobile terminal network, which can not only select the target network dynamically, but also solve the problem regarding the inconsistent units of the network parameters of various networks in the method of the embodiment 1, and further demonstrates the user' s satisfaction level with each of the network parameters.

Hereinafter, the method is further described with reference to an embodiment 2, and Fig. 4 is the flowchart of the embodiment 2.

In this method, the expected values are provided respectively to correspond with the network parameters of concern to the user, and the expected values for the network parameters are set by the user or by the various application services. The level of concern to the user to various network parameters can be represented by the weighted values set for the network parameters; the particular needs by the user to the network parameters can be represented by the expected values set for the network parameters. After the expected values have been provided, if it is assumed that the multi-mode MT is located in a current network, the network parameters concerned by the user are monitored in each available network in the step 401. In the step 402, the user strategy is monitored. In the step 403, the expected values for each network parameters are monitored.

In the step 404, when various available networks are affected by practical factors, if the network parameters monitored by the MT in various available networks are changed, the corresponding network parameters are updated by the MT in the step 405; otherwise, the monitoring continues.

In the step 406, if the weighted values of the network parameters are reset by the user, i.e. the user strategy is changed, the user strategy information, i.e. the weighted values of the relevant network parameters, are updated by the MT in the step 407 ; otherwise, the monitoring continues.

In the step 408, if the user reset the expected values for the corresponding network parameters, leading to the changes in the expected values, the expected values are updated by the MT in the step 409; otherwise, the monitoring continues.

In the step 410, if all of the network parameters monitored by the MT, the corresponding user strategy and the expected values for the corresponding network parameter are not changed or updated, then the network selection is not performed in the step 413; otherwise, the updating is performed by the MT in the step 411 and the function value of the each available network is calculated on the basis of the network parameters in the available network, and the corresponding user strategy and the expected values for the corresponding network parameters are calculated according to the following functional relationship for the function value of each available network: N γ

wherein, f is the function value of the available network, V₁ is the network parameter of concern to the user, W₁ is the weighted value of V₁ set by the user, E₁ is the expected value of V₁, and N is the total number of the network parameters, and the unit of E₁ is the same as that of V₁. The monitored value of the network parameter is divided by the expected value for this network parameter, i.e., calculating — V*- , so as to obtain a value denoting

the user's satisfaction level with the network parameter.

After the function value of each available network has been obtained, the available network with the maximum function value is selected as the target network in the step 412. If there are more than one available networks with the same maximum function value, then the network in which the MT is currently located is selected as the target network.

Hereinafter, the method of the embodiment 2 is further described with reference to Fig. 2. Assuming the MT is located in two available networks at the same time, one is a WLAN network; the other a CDMA/1X network. The network parameters and the corresponding user strategy saved in the MT are currently shown in Table 5. It can be seen in Table 5 that the network parameters of concern to the user are "cost", "bandwidth", and "security level", and the corresponding weighted values of the network parameters of concern to the user are set by user as 0.1, 0.7, and 0.2 respectively; also, the corresponding expected values for various network parameters are set by the user respectively as 1 Yuan/hour, 500 Kbit/s, and 5. The level of concern by the user for each network parameter can be presented by the user strategy, for example of most concern to the user is the bandwidth that can be provided by the network, the second one is the security level of the network, and the last one is the cost . The user' s particular needs for each network parameter can be represented by the expected value of each network parameter. Table 5

By calculation, the function value of the WLAN network obtained is: f_w =0.1x(l/2)+0.7x(200/500) +0.2x(5/5) = 0.53 ; and the function value of

the CDMA/1X network is: f_c =0.1x(l/l) +0.7x(300/500)+0.2x(3/5) = 0.64 , so the CDMA/1X network is selected by the MT.

When using the method discussed above, when the user is highly concerned about a certain parameter, a higher weighted value will be set for this parameter, but the user actually intends to reduce the parameter, for example the parameters such as the "cost" or "power consumption". When the user is concerned about "cost" or "power consumption" and sets higher parameters for them, the user usually intends to have lower cost or power consumption; for this kind of network parameter, the satisfaction degree should be set

E as — for the user, so that it can really meet the user's needs.

The network parameters, the corresponding user strategy and the corresponding expected values of the network parameters are monitored by the MT. Assuming the network parameter "bandwidth" in the WLAN network is changed, the corresponding parameter stored in the MT is updated by the MT, and the updated network parameters, the corresponding user strategy and the corresponding expected values of the network parameter are shown in Table 6. Table 6

When the changes of the network parameters are monitored by the MT, the function values for the two networks are recalculated, here

/_r=0.1x(l/2)+0.7x(300/500)+0.2x(5/5) = 0.67 ; and the function value of

CDMA/1X is /_c=0.1x(l/l)+0.7x(300/500) +0.2x(3/5) = 0.64 , so the WLAN network is selected by the MT as the target network.

In the embodiment 2, the expected values of the network parameters are set by the user, but when the user selects a different application service, such as Voice over IP (VoIP) and Instant Message (IM) , the different application services have different expected needs, while the expected values set by the user himself may be quite different from the needs for the network parameters by the different application service. In order to meet the needs for the application service, the expected values can be set by the MT according to the needs by the different application service. For example, when the VoIP service is performed by the MT, the need for the network parameter "bandwidth" is 500 Kbit/s, so the expected value for the bandwidth is set by MT as 500 Kbit/s; when the MT operates an IM service, the need for the network parameter "bandwidth" is 10 Kbit/s, so the expected value for the bandwidth is set by the MT as 10 Kbit/s . As to the other parameters, it works in the same way, so there is no need to repeat the description.

If the MT operates simultaneously a number of M application services, the needs of the M application services can be combined to set the expected values for the corresponding network parameters. For example, the expected value for the corresponding network

M parameters can be set according to the function E₁ = ^~∑S -E , wherein

E₁ is the expected value of the network parameter, E₁₃ is the need value of each application service for the network parameter, and S_j is the weighted value corresponding to E₁₃. More particularly, assuming the VoIP service and the IM service are performed simultaneously by the MT while the needs of the VoIP service and the IM service for the network parameter "bandwidth" are 500 Kbit/s and 10 Kbit/s respectively, the combined need of the two is Slx500KbitIs +S2xlOKbitIs . For the sake of simplicity, Sl and S2 are both set as 1, so the combined need of the two is 500 Kbit/s + 10 Kbit/s = 510 Kbit/s, and the expected value for the network parameter "bandwidth" is set by the MT as 510 Kbit/s. As to the other parameters, it works in the same way, so there is no need to repeat the description.

In the method according to this invention, the user directly sets the weighted value W₁ for the network parameter concerned by him,

N

W₁ set by the user should satisfy the conditions : O≤røζ≤l and ^₁W₁=I.

Wherein, N is the total number of the network parameters of concern to the user. In practical applications, it is possible not to use the parameters set directly by the user as the weighted value of the network parameter, in this case, when the user sets parameters for the network parameters of concern to him, the level of concern for the corresponding network parameters can be represented by the parameters, but that parameter does not act as the weighted value directly, and in this case, the user does not need to set the network parameters of concern to him according to the above conditions. Here, the processing of the parameters set by the user should be performed by the MT, then the processed parameters are used as the weighted value of the various corresponding network parameters. The processing of the parameters set by the user is performed as following: assuming the parameter set by the user is W₁, by

N calculating ∑w_t to obtain the sum of the parameter W₁ set by the

w user; and by calculating W₁ =—^-^L— to obtain the corresponding

weighted value W₁. Wherein, N is the total number of the parameters set by the user.

More particularly, assuming the parameters set by the user for the network parameters "cost", "bandwidth", and "security level" are 10, 25 and 15 respectively, it can be seen that of most concern to the user is the bandwidth, the second one is the security level, and the last one is the cost. The weighted values of "cost",

"bandwidth", and "security level" are , , and

10 + 25 + 15 10 + 25 + 15 , i . e . 0 . 2 , 0 . 5 , and 0 . 3 , respectively .

10 + 25 + 15

In the method discussed by this invention, when there are more than one available networks with the same maximum function value, if the function value of the current network in which the mobile terminal is located is the largest, the current network of the mobile terminal is selected as the target network; otherwise, one of the available networks with the maximum function value is selected randomly as the target network, or one of the available networks with the maximum function value is selected according to a pre-set condition.

There are many ways to store the network parameters, the corresponding user strategy and the corresponding expected values of the network parameters in the MT, but in the method of the present invention, a data table method is used to store said corresponding parameters .

A network status table is used to store the monitored values of the network parameters, a user strategy table is used to store the weighted values of the network parameters concerned by the user, and an expected value storage table is used to store the expected values of the corresponding network parameters set by the user or by the application service.

The network status table includes the three items of a network marker, a network name, and a network parameter N, wherein the network marker can indicate the marker of an available network, the network name records the name of the available network, such as "ISPl-WLAN", and the network parameter N is used to store the monitored value of the Nth corresponding network parameter.

The user strategy table includes the four items of a network parameter marker, a network parameter name, a weighted value of the network parameter, and the expected value of the network parameter.

The expected value storage table includes the three items of a network parameter marker, a network parameter name, and an expected value, and if the expected value is set by the MT for different application services, the expected value storage table also includes the two items of an application service name and an application service need value.

In the above described embodiment, the WLAN network, CDMA/1X network and the network parameters "cost", "bandwidth" and "security level" are used by way of example for explanation, as to any other methods and/or other network parameters, the method of the present invention is applicable in the same say therefore no repeated explanation is needed here.

Based on the above method, the present invention also provides an apparatus for selecting a mobile communication network. Hereinafter, the apparatus is further described with reference to an embodiment .

Fig.5 is an illustrative diagram of the apparatus, which includes a monitoring unit 51, a determining unit 52, a function value acquiring unit 53, and a network selecting unit 54, and the apparatus is provided in the MT.

When the MT is located in a current network, the network parameters of concern to the user in each of the available networks and the parameters relevant to the network parameters are monitored by the monitoring unit 51. The determining unit 52 determines whether said network parameters and/or the relevant parameters monitored by the monitoring unit 51 are changed and updated, and the determined result is sent to the function value acquiring unit 53. After the function value acquiring unit 53 has received the determined result from the function value acquiring unit 52, if said network parameters and/or the relevant parameters have been changed and updated, the function value of each available network is obtained according to said network parameters and/or the relevant parameters, and the function value of each available network is sent to the network selecting unit 54. In the network selecting unit 54, after the function value of each available network from the function value acquiring unit 53 has been received, the available network with the maximum function value is selected as a target network.

The parameter relevant to the network parameters monitored by the monitoring unit 51 can be the weighted value of said network parameter or the weighted value of said network parameter and the excepted value of said network parameter.

If the parameters relevant to the network parameters monitored by the monitoring unit 51 are the weighted values of said network parameters, then the function value acquiring unit 53 comprises a multiplying unit 531 and an accumulating unit 532, as shown in Fig. 6.

By the multiplying unit 531, W₁-V₁ can be calculated to obtain the weighted value of the network parameter; and by the accumulating

N unit 532, J = ^W₁-V₁ can be calculated to obtain the function value

of the available network. Wherein, f is the function value of the available network, V₁ is the network parameter of concern to the user, W₁ is the weighted value of V₁, and N is the total number of the network parameters .

If the parameters relevant to the network parameters monitored by the monitoring unit 51 are the weighted values of the network parameters and the expected values of the network parameters, then said function value acquiring unit 53 comprises a dividing unit 533, a multiplying unit 534 and an accumulating unit 535, as shown in Fig. 7.

V

Said dividing unit 533 is used to calculate —*- to obtain the user' s

satisfaction level with the network parameters, said multiplying

V unit 534 is used to calculate W_l-(-^J-) to obtain the weighted value

^E, of said satisfaction level, and said accumulating unit 535 is used to calculate to obtain the function value of the

available network. Wherein, f is the function value of the available network, V₁ is the network parameter of concern to the user, W₁ is the weighted value of V₁, E₁ is the expected value of V₁, and N is the total number of the network parameter.

As shown in Fig. 7, said apparatus further comprises an expected value setting unit 55 for setting said expected value of the network parameter, and the user can set said expected value E₁ of the network parameter via the expected value setting unit 55, or said expected value E₁ of the network parameter can also be set by the MT via the expected value setting unit 55 according to the needs of at least one application service.

When at least one application service is performed by the mobile terminal, said expected value setting unit 55 comprises a need value weighting unit 551 and a weighted value accumulating unit 552, as shown in fig . 8 .

The need value weighting unit 551 calculates S_J-E_ιj to obtain the weighted value of the need value of the application service for the network parameter V₁; and the weighted value accumulating unit 552

M calculates E₁=^S_j-E_1J to obtain and set the expected value E₁ of

the network parameter V₁. Wherein, E₁₃ is the need value of different application services for the network parameter V₁, S₃ is the weighted value corresponding to E₁₃, and M is the total number of the application services.

In the apparatus according to the present invention, it is possible to use directly a coefficient for the network parameter set by the user as the weighted value W₁ of the network parameter V₁, and it is also possible not to used directly a coefficient for the network parameter set by the user as the weighted value W₁ of the network parameter V₁. When the weighted value W₁ is not the coefficient set by the user directly, said apparatus further comprises a summing unit 501 and a weighted value acquiring unit 502, as shown in Fig. 9.

Assuming the coefficient set by the user for the network parameter

N

V₁ is W₁, by calculating ∑w_t via the adding unit 501 to the

coefficient W₁ set by the user, it is obtained the sum of all the w W₁; then by calculating W₁ = _N ' via the weighted value acquiring

unit 502, the weighted value W₁ of the network parameter V₁ is obtained and set. Wherein, N is the total number of the network parameters .

The above described embodiments are merely the preferred embodiments of the present invention, and they are by no means intended to limit the scope of the present invention; therefore, any modification, equivalent substitution, refinements, etc., as long as it is within the scope of the spirit and principles of the present invention, would fall within the scope of protection of the present invention.

Claims

1. A method for selecting a mobile communication network, characterized by comprising: monitoring a network parameter of concern to a user and a parameter relevant to said network parameter in each of available networks, wherein if said network parameter and/or said relevant parameter are/is changed, a function value of each of the available networks is obtained on the basis of said network parameter and said relevant parameter, and the available network with the maximum function value is selected as a target network.

2. The method according to claim 1, wherein when said relevant parameter is a weighted value of said network parameter, the function value of the available networks is obtained by the following steps: calculating W₁-V₁ to obtain the weighted value of the network parameter; and

N calculating I = ^W₁-V₁ to obtain the function value of the available

networks, wherein, f is the function value of the available networks, V₁ is the network parameter of concern to the user, W₁ is the weighted value of V₁, and N is the total number of the network parameter (s) .

3. The method according to claim 1, wherein when said relevant parameter is the weighted value of the network parameter and an expected value of the network parameter, the function value of the available networks is obtained by the following steps:

V calculating —- to obtain the user's satisfaction level to the

E₁ network parameter;

V calculating W •(—^L) to obtain the weighted value of said

E₁ satisfaction level; and Λ^ γ calculating f = _/\W₁-(—'-) to obtain the function value of the

available networks, wherein, f is the function value of the available networks, V₁ is the network parameter of concern to the user, W₁ is the weighted value of V₁, E₁ is the expected value of V₁, and N is the total number of the network parameter (s) .

4. The method according to claim 3, wherein said expected value E₁ of said network parameter is set by the user or by the mobile terminal according to a need for at least one application service.

5. The method according to claim 4, wherein when at least one application service is performed by the mobile terminal and the expected value of the network parameter is set by the mobile terminal according to the following steps : calculating S_j -E_1J to obtain the weighted value of a need value of the application service for the network parameter V₁; and

M calculating E₁ =^~∑S -E to obtain and set the expected value E₁ of

the network parameter V₁, wherein, E₁₃ is the need value of different application service for the network parameter V₁, S₃ is the weighted value corresponding to E_1J, and M is the total number of the application service (s) .

6. The method according to one of claims 2 to 5, wherein when the weighted value W₁ is set directly by the user, W₁ is set by the following conditions:

wherein, N is the total number of the network parameter (s) .

7. The method according to one of claims 2 to 5, wherein when the weighted value W₁ is not a coefficient set directly by the user, W₁ is set by the following steps: setting a coefficient W₁ for the network parameter V₁ by the user;

N calculating ∑w_t to obtain the sum of all the W₁; and

w calculating W₁ = —^-^L— to obtain and set the weighted value W₁ of the

8. The method according to one of claims 1 to 5, wherein when there are more than one available networks with the maximum function value, if the network in which the mobile terminal is currently located has the maximum function value, then the network in which the mobile terminal is currently located is selected as the target network, otherwise, one of the available networks with the maximum function value is selected randomly as the target network, or one of available networks with the maximum function value is selected on the basis of a predetermined condition.

9. An apparatus for selecting a mobile communication network, characterized by comprising: a monitoring unit for monitoring a network parameter of concern to the user and a parameter relevant to said network parameter in each of the available networks; a determining unit for determining whether relevant monitored value obtained by the monitoring unit is changed; a function value acquiring unit for receiving information from the determining unit, and for obtaining the function value of each of the available networks according to the monitored value if the relevant monitored value is being changed, ; and a network selecting unit for receiving the function value obtained by the function value acquiring unit, and for selecting the available network with the maximum function value as a target network.

10. The apparatus according to claim 9, wherein when said relevant parameters are weighted value of the network parameters, said function value acquiring unit comprises: a multiplying unit for calculating W₁-V₁ to obtain the weighted value of the network parameter; and

N an accumulating unit for calculating Z = ^₁W₁-V₁ to obtain the

function value of the available network, wherein, f is the function value of the available network, V₁ is the network parameter of concern to the user, W₁ is the weighted value of V₁, and N is the total number of the network parameter (s) .

11. The apparatus according to claim 9, characterized in that, when said relevant parameter is a weighted value of said network parameter and an expected value of the network parameter, said function value acquiring unit comprises: a dividing unit for calculating — V- to obtain a satisfaction level

of the user for the network parameter;

V a multiplying unit for calculating røζ •(—*-) to obtain a weighted

value of said satisfaction level; and

an accumulating unit for calculating f = ∑W₁-(—'-) to obtain the

function value of the available network, wherein, f is the function value of the available network, V₁ is the network parameter of concern to the user, W₁ is the weighted value of V₁, E₁ is the expected value of V₁, and N is the total number of the network parameter (s) .

12. The apparatus according to claim 11, wherein said apparatus further comprises an expected value setting unit for setting the expected value of said network parameter.

13. The apparatus according to claim 12, wherein the expected value of said network parameter is set by the user via the expected value setting unit, or by the mobile terminal via the expected value setting unit according to a need for at least one application service .

14. The apparatus according to claim 13, wherein when at least one application service is performed by the mobile terminal, said expected value setting unit comprises: a need value weighting unit for calculating S -E to obtain a weighted value of the need value of the application service for the network parameter V₁; and

M a weighted value accumulating unit for calculating E₁ = ^S ^■ E to

obtain and set the expected value E₁ of the network parameter V₁, wherein, E₁₃ is the need value of different application services for the network parameter V₁, S₃ is the weighted value corresponding to E_1J, and M is the total number of the application service (s) .

15. The apparatus according to one of claims 9 to 14, wherein when the weighted value W₁ is not a coefficient set directly by the user, said apparatus further comprises:

N a summing unit for calculating ∑w_; for the coefficient W₁ set by

the user to obtain the sum of all the W₁; and

a weighted value acquiring unit for calculating W₁ = to obtain

and set the weighted value W₁ of the network parameter V₁, wherein, N is the total number of the network parameter (s) .