WO2014040283A1 - Network switching method and device, base station, and base station controller - Google Patents

Abstract

Provided are a network switching method and device, a base station, and a base station controller. The method comprises: receiving a network switching request sent by a terminal, the network switching request comprising an identifier of the current service of the terminal; determining the service feature of the current service according to the identifier, and selecting more than two networks matching the service feature; and selecting a network with poor applicability and/or a large relative residual capacity in the more than two networks as a target network to which the terminal is switched, the relative residual capacity being the ratio of the residual capacity, represented by equivalent spectral bandwidth, of each network in the more than two networks to the total spectral bandwidth of the network. The above method solves the problems in the prior art that the network resource distribution is unreasonable and the network resource utilization rate is low.

Description

 The present invention relates to communications technologies, and in particular, to a method and apparatus for network handover, a base station, and a base station controller. Background technique

 At present, there are multiple radio access network coverages in the same area. Each access technology uses a unique access model and a radio resource management strategy. This separate operation mode is not conducive to increasingly tight radio resources (such as frequency bandwidth). Make full use of it.

 Therefore, with the rapid development of multi-mode terminal technology and heterogeneous network collaboration technology, heterogeneous wireless network resource convergence is an inevitable trend in the future development of wireless communication networks. In response to this problem, 3GPP introduced public radio resource management (Common Radio Resource).

Management, referred to as CRRM).

 In a heterogeneous network environment with multiple radio access technologies, CRRM can improve the performance of the entire heterogeneous network through optimized resource management. Specifically, the application network environment of the CRRM is: a) multiple different access networks are jointly covered in the same area; b) each radio access network (such as the Radio Access Network, referred to as RAN) has optimized radio resource management. (Radio Resource Management, RRM for short); c) Multi-mode terminal capable of accessing multiple radio access networks and access technologies, modes, and cells.

 CRRM proposes the concept of resource pool. A resource pool may contain multiple access technologies, such as Global System for Mobile Communication (GSM) and Wideband Code Division Multiple Access (WCDMA). Long Term Evolution (LTE), etc., the CRRM guides users to access the most suitable resource pool in the ideal link mode.

In the CRRM protocol, when the target base station controller (BSC) or the radio network controller (RNC) receives the handover or relocation request message, the remaining resources of the target cell are first and current. If the remaining resources of the serving cell are compared, if the remaining resources of the target cell are large, the handover is allowed, otherwise it is rejected. That is to say, the current selection of networks for the purpose of capacity balancing can bring about the benefits of making full use of network capacity, but the above techniques have the following disadvantages:

 The remaining capacity of different networks (system capacity minus the capacity already occupied by users) is incomparable; specifically, because the wireless resources of different networks are expressed differently, the remaining capacity cannot be directly compared. For example, GSM is time division multiple access, so its remaining capacity is how many time slots remain. LTE is orthogonal frequency division multiple access, so its remaining capacity is how many subcarriers remain. From this point of view, LTE and GSM cannot directly compare the remaining capacity.

 As a result, the network is only selected by the remaining capacity, resulting in unreasonable allocation of network resources and low utilization of network resources, which may easily cause a problem of a large call blocking rate in a service with poor access capability (such as a streaming service). Summary of the invention

 In view of this, the embodiments of the present invention provide a method and a device for network handover, a base station, and a base station controller, which are used to solve the problem that the network resource allocation in the prior art is unreasonable and the network resource utilization rate is low.

 In a first aspect, an embodiment of the present invention provides a method for network switching, including:

 Receiving a network handover request sent by the terminal, where the network handover request includes: an identifier of the current service of the terminal;

 Determining, according to the identifier, a service feature of the current service, and selecting two or more networks that match the service feature;

 Selecting a network with poor applicability and/or a relatively large remaining capacity in the two or more networks as a target network for the terminal handover;

 The relative remaining capacity is the ratio of the remaining capacity represented by the equivalent spectral bandwidth of each of the two or more networks to the total spectral bandwidth of the network.

 With reference to the first aspect, in a first possible implementation, the foregoing method for network switching further includes: if the network matching the service feature is selected as one, the selected network is switched by the terminal Target network.

With reference to the first aspect and the foregoing possible implementation manner, in a second possible implementation manner, The method for network handover further includes: sending a network handover response to the terminal, where the network handover response includes an identifier of the selected target network.

 With reference to the first aspect and the foregoing possible implementation manner, in a third possible implementation, the service feature includes:

 Session-type business characteristics, interaction-type business characteristics, flow-type business characteristics, or background-type business characteristics. With reference to the first aspect and the foregoing possible implementation manner, in a fourth possible implementation, the selecting, in the two or more networks, a network with poor applicability and/or a relatively large remaining capacity is used as the terminal switching. Before the steps of the target network, it also includes:

 Obtaining a remaining capacity of each of the two or more networks and an equivalent spectrum bandwidth respectively occupied by the current service of the terminal in the two or more networks.

 With reference to the first aspect and the foregoing possible implementation manner, in a fifth possible implementation manner, the selecting, in the two or more networks, a network with poor applicability and/or a relatively large remaining capacity is used as the terminal switching The process of the target network, including:

W _i - v ⁱ

M ^J _{i =} R ^J + a ¹

According to ^W ′′, the network corresponding to the minimum 选择 is selected as the target network for the terminal handover;

Among them, belong to ('', ^ {(1,1), (1,2), (1,3), (2,2), (2, 3), (3,3), (4,2) , (4,3)}, _RJ represents the preset network applicability parameter, ^ represents the total spectrum bandwidth in the network corresponding to ^, ^ represents the remaining capacity of the network corresponding to R ^J , "represents the relative remaining A constant for the weight of capacity and business characteristics.

 With reference to the first aspect and the foregoing possible implementation manner, in a sixth possible implementation, the two or more networks include: an LTE system, a GSM system, and a WCDMA system;

Obtaining, for the LTE system, an equivalent spectrum bandwidth in the LTE system according to the following formula (1); and acquiring a remaining capacity in the LTE system according to the following formula (2); Equation (3) acquires an equivalent spectral bandwidth in the GSM; and acquires a remaining capacity in the GSM system according to the following formula (4); For the WCDMA system, obtaining an equivalent spectral bandwidth in the WCDMA system according to the following formula (5); and acquiring a remaining capacity in the WCDMA system according to the following formula (6);

Formula 1 )

Formula (2): Ψ _Ί - Ν · δ, -K_K N _A *d where ^ denotes the preset subcarrier bandwidth, denotes the preset ^φ , the activation factor of the class service, and C denotes the total preset in the LTE system The number of subcarriers, „ indicates the preset ^φ , the rate of the “user” in the class service;

^ denotes the measured ^φ , the channel gain of the "user" on the first subcarrier in the class service, σ ² represents the measured noise power, ^ represents the acquired ^Φ , the "average user average power" in the class service, indicating the calculation acquisition The number of subcarriers allocated to the wth user in the ^ class service is a coefficient, ^«-1.5/^(55^).

^ indicates the system capacity preset in the LTE system, and the ^NNN indicates the number of users having the session type service, the interactive type service, the flow type service, and the background type service in the LTE system, respectively, and ^{δ δ2} and ^{d δ4} respectively represent The equivalent bandwidth of the session type service, the interaction type service, the flow type service, and the background type service in the LTE system;

Formula (3) ⁼ constitution ^z

Formula (4) ^0 = ^0-^ where represents the equivalent spectral bandwidth of the session class service in the GSM system. Representing the total spectrum bandwidth preset in the GSM system, indicating the number of users having session-type services in the GSM system; Equation ( 5 ) ^d i = ^{35 kHz} ' ^d 2 = 8 .5^Hz , d ₄ = 60.2kHz

Formula (6) X ^{= W} " ^N ' ^d _ ^N 2 ' ^d f ^N 4 4

Where ^ represents the total spectrum bandwidth preset in the WCDMA system, and NN ₂ and N represent the number of users of the session type service, the interaction type service, and the background type service in the WCDMA system, d δ ₂ , respectively Indicates the equivalent spectrum bandwidth of the session-type service, the interactive-type service, and the background-type service in the WCDMA system.

 In a second aspect, an embodiment of the present invention provides a device for network switching, including:

 a receiving unit, configured to receive a network switching request sent by the terminal, where the network switching request includes: an identifier of a current service of the terminal;

 a selecting unit, configured to determine, according to the identifier, a service feature of the current service, and select two or more networks that match the service feature;

 a target network selecting unit, configured to select a network with poor applicability and/or a relatively large remaining capacity in the two or more networks as a target network for the terminal handover;

 The relative remaining capacity is the ratio of the remaining capacity represented by the equivalent spectral bandwidth of each of the two or more networks to the total spectral bandwidth of the network.

 With reference to the second aspect, in a first possible implementation, if the network selected in the selecting unit that matches the service feature is one, the target network selecting unit is further combined with the second aspect and The foregoing possible implementation manner, in the second possible implementation manner, the foregoing apparatus for network switching further includes:

 And a sending unit, configured to send a network switch response to the terminal, where the network switch response includes an identifier of the selected target network.

 With reference to the second aspect and the foregoing possible implementation manner, in a third possible implementation manner, the service feature includes:

Session-type business characteristics, interaction-type business characteristics, flow-type business characteristics, or background-type business characteristics. With reference to the second aspect and the foregoing possible implementation manner, in a fourth possible implementation, the foregoing apparatus for network switching further includes: an acquiring unit, configured to acquire a remaining capacity of each of the two or more networks, and The equivalent spectrum bandwidth occupied by the terminal in the two or more networks.

 With reference to the second aspect and the foregoing possible implementation manner, in a fifth possible implementation manner, the target network selecting unit is specifically used to

W _i - x ⁱ

M ^J = R ^J + a ¹

 According to ^, the network corresponding to the minimum 选择 is selected as the target network of the terminal switching;

Among them, · belong to ('·, ·) ^e { i), (i, 2), (i, ³ ), ( ² , ² ), ( ² , ³ ), ( ³ , ³ ), ( ⁴ , ² ) The parameter in ( ⁴ , ³ )} indicates the preset network applicability parameter, ^ indicates the total spectrum bandwidth in the network corresponding to ^, ^ indicates the remaining capacity of the network corresponding to R ^J , " indicates the relative remaining capacity And the constant of the weight of the business feature.

 With reference to the second aspect and the foregoing possible implementation manner, in the sixth possible implementation, if the two or more networks include: an LTE system, a GSM system, and a WCDMA system;

 Then, the acquiring unit is specifically used to

Obtaining, for the LTE system, an equivalent spectrum bandwidth in the LTE system according to the following formula (1); and acquiring a remaining capacity in the LTE system according to the following formula (2); Equation (3) acquires an equivalent spectrum bandwidth in the GSM; and acquires a remaining capacity in the GSM system according to the following formula (4); for the WCDMA system, acquires the WCDMA system according to the following formula (5) The equivalent spectral bandwidth; and obtaining the remaining capacity in the WCDMA system according to the following formula (6); Formula 1 )

Equation (2) 2 = W ₂ - N d _l - N ₂ 'd ₂ - N ₃ 'd ₃ - N ₄ 'd ₄ ^ where represents the preset subcarrier bandwidth, indicating the preset ^Φ , class service Activation factor, C indicates the total number of subcarriers preset in the LTE system, ?, „ indicates the preset ^φ , the rate of the “user” in the class service;

<3⁄4„ denotes the measured Φ, the channel gain of the “user” on the first subcarrier in the class service, σ ² represents the measured noise power, ^ represents the acquired ^Φ , the “average user average power” in the class service, Calculating the obtained number of subcarriers allocated to the wth user in the service, as a coefficient, ^«-1.5/^(55^). ^ indicates the system capacity preset in the LTE system, and ^NNN indicates The number of users of the session type service, the interaction type service, the flow type service, and the background type service in the LTE system, ^{δ δ2} and ^{d δ4} respectively represent the session type service, the interaction type service, the flow type service, and the background in the LTE system. Equivalent bandwidth of the class service;

Formula (3) ⁼ constitution ^z

 Formula (4) ^0 = ^0 -^

 Where ^ represents the equivalent spectral bandwidth of the session-type service in the GSM system. Representing the total spectrum bandwidth preset in the GSM system, indicating the number of users who already have session-type services in the GSM system;

Equation ( 5 ) ^d i = ^35kHz ' ^d 2 = 89.5kHz , d ₄ = 60.2kHz

Formula (6) X ^{= W} " ^N ' ^d _ ^N 2' ^d 2_N ₄ 'd ₄

Where ^ represents the total spectrum bandwidth preset in the WCDMA system, N, N ₂ , N The number of users of the session type service, the interaction type service, and the background type service in the WCDMA system, d δ ₂ , respectively represent the equivalent spectrum bandwidth of the session type service, the interaction type service, and the background type service in the WCDMA system. . In a third aspect, an embodiment of the present invention provides a base station, including the apparatus for network switching according to any one of the foregoing.

 According to a fourth aspect, an embodiment of the present invention provides a base station controller, including the apparatus for network switching according to any one of the foregoing.

 According to the foregoing technical solution, the method and device for network handover, the base station, and the base station controller according to the embodiment of the present invention determine the service characteristics of the current service according to the identifier of the current service of the terminal, and then select two or more networks that match the service characteristics. Further, the network with poor applicability and/or relatively large remaining capacity is selected as the target network switched by the terminal to achieve reasonable allocation of heterogeneous network resources, improve utilization of heterogeneous network resources, and reduce terminal services. Call blocking rate. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solution of the present invention, a brief description of the drawings to be used in the embodiments will be briefly described below. It is obvious that the following drawings are only drawings of some embodiments of the present invention, Those skilled in the art can obtain other drawings which can also implement the technical solutions of the present invention according to the drawings without any creative labor.

 1 is a schematic flowchart of a method for network switching according to an embodiment of the present invention;

 2 is a schematic structural diagram of a method for network handover according to an embodiment of the present invention; FIG. 3 is a schematic flowchart of a method for network handover according to an embodiment of the present invention; FIG. 4 is a schematic diagram of TDMA in a GSM system according to an embodiment of the present invention; Schematic diagram of the system access mode;

 5A is a relationship diagram of equivalent bandwidth and average power of a session type service in an LTE system according to an embodiment of the present invention;

 FIG. 5B is a diagram showing a relationship between equivalent bandwidth and average power of an interactive service in an LTE system according to an embodiment of the present invention; FIG.

FIG. 5C is an equivalent bandwidth and peace of a flow service in an LTE system according to an embodiment of the present invention. Relationship diagram of average power;

 FIG. 5D is a diagram showing a relationship between equivalent bandwidth and average power of a background type service in an LTE system according to an embodiment of the present disclosure; FIG.

 FIG. 6 is a schematic diagram of a network applicable to various types of services according to an embodiment of the present invention; FIG. 7A is a simulation diagram of a call blocking rate of a session type service in a heterogeneous network according to an embodiment of the present invention;

 FIG. 7B is a simulation diagram of a call blocking rate of an interactive service in a heterogeneous network according to an embodiment of the present invention; FIG.

 7C is a simulation diagram of a call blocking rate of a flow service in a heterogeneous network according to an embodiment of the present invention;

 7D is a simulation diagram of a call blocking rate of a background type service in a heterogeneous network according to an embodiment of the present invention;

 FIG. 8 is a schematic structural diagram of a network switching apparatus according to an embodiment of the present invention; FIG. 9A is a schematic structural diagram of a network switching apparatus according to an embodiment of the present invention; FIG. 9B is a schematic structural diagram of a network switching apparatus according to an embodiment of the present invention; . detailed description

 The technical solutions of the present invention will be clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It will be apparent that the various embodiments described below are merely exemplary embodiments of the invention. Based on the following various embodiments of the present invention, those skilled in the art can obtain other technical features that can solve the technical problems of the present invention and achieve the technical effects of the present invention by equivalently transforming some or even all of the technical features without creative work. The various embodiments of the invention are apparent from the scope of the invention as disclosed.

 The user in any of the following embodiments refers to a user terminal, and the embodiment of the present invention replaces the user terminal with a user for convenience of description.

In the prior art, there are four basic types of communication services: a session type service, an interaction type service, a stream type service, and a background type service. Different types of services can be accessed by different types of services. Session services can be connected to GSM systems, WCDMA systems, and LTE systems. This is called strong access capability; It is possible to access the LTE system, but it is not suitable for accessing the GSM system, which is called weak access capability. In addition, the interactive service can access the WCDMA system and the LTE system, and the background service can access the WCDMA system and the LTE system. Therefore, the access capability of the interactive service and the background service is the same, and the access capability is generally called.

 The GSM system has the most single bearer service and is only suitable for accessing session-type services. It is called network poorly applicable. The LTE bearer service is the most abundant and can support all services. It is called network adaptability. Therefore, the session service can be connected to the GSM system first. If the session service also accesses the LTE system in a large amount, the video service belonging to the stream service may face insufficient network resources. At this time, there may be remaining capacity in the GSM system. However, since the GSM system is not suitable for accessing video, the above video service cannot access the network.

 Thus, based on the algorithm of the remaining capacity selection network, the remaining capacity of each network is unmatched. Further, the existing algorithms do not consider service characteristics, resulting in a problem of large call blocking rate and low resource utilization rate of the network.

 In the specific application process, the current CRRM does not include the business characteristics in the calculation range when selecting the network. In the embodiment of the present invention, the network is selected by the two factors of the integrated service feature and the remaining capacity of the network. For example, the time slots, code channels, and orthogonal carriers (OFDMA of the LTE system) occupied by the services in the GSM system, the WCDMA system, and the LTE system are mapped to equivalent spectrum bandwidths (hereinafter referred to as equivalent bandwidths), and the remaining capacity is unified. The remaining equivalent spectrum bandwidth (ie, the remaining capacity is the total spectrum bandwidth in the system (hereinafter referred to as the system bandwidth) minus the equivalent spectrum bandwidth occupied by the accessed users), so that the remaining capacity between different systems can be compared. In the embodiment of the present invention, the characteristics of the services that can be accessed by different types of services are different. Therefore, the service features are classified into four types, including: session-type service features, interaction-type service features, flow-type service features, and background services. feature.

If a service belongs to the session type service, the service feature of the session type service may be provided. Correspondingly, if a service belongs to the interaction type service, the service feature of the interaction type service is performed, and the service characteristic of the service of the service is performed. It can be understood that the service can access the characteristics of different networks. FIG. 1 is a schematic flowchart of a method for network switching according to an embodiment of the present invention. As shown in FIG. 1, the method for network switching in this embodiment is as follows.

 101. The network switch request sent by the terminal is received, where the network switch request includes: an identifier of the current service of the terminal.

 In this embodiment, the identifier of the current service of the terminal is used to uniquely identify the service type, for example, 1, 2, 3, and 4 mentioned in the following formula; wherein, = 1 indicates a session type service, and = 2 indicates an interaction type service. , =3 indicates the flow class service, and =4 indicates the background class service.

 Of course, in actual applications, the identifier of the current service of the terminal is recognized by both the terminal and the base station.

102. Determine, according to the identifier, a service feature of the current service, and select two or more networks that match the service feature.

 For example, the service features in this embodiment include: a session type service feature, an interaction class service feature, a flow class service feature, and a background class service feature.

 The current session type service is applicable to the GSM system, the WCDMA system, the LTE system, etc.; the interactive service and the background service are applicable to the WCDMA system and the LTE system; and the flow service is applicable to the LTE system.

 103. Select a network with poor applicability and/or a relatively large remaining capacity in two or more networks as a target network for the terminal handover; and the relative remaining capacity is an equivalent spectrum bandwidth for each of the two or more networks. The ratio of the remaining capacity represented to the total spectrum bandwidth of the network.

 In a preferred usage scenario, step 103 may be to select a network with poor applicability in two or more networks and a relatively large remaining capacity as a target network for terminal handover.

 In another usage scenario, step 103 may also be to select a network with poor applicability in two or more networks as the target network for terminal handover. A large number of networks serve as the target network for terminal handover.

This embodiment does not limit the specific implementation manner of step 103, and may be based on actual conditions. Choose Execute.

 The above network switching method, for a certain service, when selecting a network, considers the relative remaining capacity of each network in the heterogeneous network on the one hand, and considers the types of services that each network can support on the other hand, so that the above services are first selected in the service. A network with poor applicability in all networks that the service can access, thereby ensuring reasonable allocation of network resources, improving network resource utilization, and reducing call blocking rate of services.

 Of course, the method for the network handover further includes: if the network matching the service feature is selected. Further, as shown in FIG. 2, the method for network switching includes the following step 104.

 104. Send a network switch response to the terminal, where the network switch response includes an identifier of the selected target network.

 In this embodiment, different network values can be used to distinguish each network. The identifier of a certain network can be understood as the parameter value corresponding to the network. For example, the parameter ·=1 is the identifier of the GSM system, and the parameter j=2. For the identification of the WCDMA system, the parameter ·=3 is the identity of the LTE system.

 Of course, in practical applications, the identifier of the network is recognized by the terminal, the base station, and the base station controller. For example, the identifier of the above network may be encoded by each network and broadcast to the terminal in its broadcast channel.

 The identifier of the above network may also be other symbols or codes that can uniquely represent the network, which is not limited in this embodiment.

 According to the foregoing embodiment, the method for network switching in this embodiment determines the service feature of the current service according to the identifier of the current service of the terminal, and then selects two or more networks that match the service feature, and further selects two or more networks. The network with poor performance and/or large residual capacity serves as the target network for the terminal to switch, realizes the reasonable allocation of the heterogeneous network resources, improves the utilization of the heterogeneous network resources, and reduces the call blocking rate of the terminal services.

FIG. 3 is a schematic flowchart diagram of a method for network switching according to another embodiment of the present invention. As shown in FIG. 3, the steps of the method for network switching in this embodiment are as follows.

 301. Receive a network switch request sent by the terminal, where the network switch request includes: an identifier of the current service of the terminal.

 302. Determine, according to the identifier, a service feature of the current service, and select two or more networks that match the service feature.

 303. Acquire respective remaining capacity of the two or more networks, and an equivalent bandwidth occupied by the current service of the terminal in the two or more networks.

 304. Select a network with poor applicability and/or a relatively large remaining capacity in the two or more networks as a target network for the terminal handover; and the relative remaining capacity is used by each of the two or more networks. The ratio of the remaining capacity represented by the equivalent spectral bandwidth to the total spectral bandwidth of the network.

W _i - x ⁱ

M ^J = R ^J + a ¹

 Specifically, in practical applications, the network corresponding to the minimum Μ/· is selected as the target network of the terminal handover according to ^.

Among them, · belong to ('·, ·) ^e { i), (i, 2), (i, ³ ), ( ² , ² ), ( ² , ³ ), ( ³ , ³ ), ( ⁴ , ² ) The parameter in ( ⁴ , ³ )} represents the preset network applicability parameter, ^ represents the system bandwidth of the network corresponding to ^ (ie the total spectrum bandwidth in the system), and represents the remaining capacity of the network corresponding to ^, "Constant that represents the weight of the remaining capacity and business characteristics.

 For example, more than two networks include: LTE systems, GSM systems, and WCDMA systems;

 For the LTE system, obtaining an equivalent spectrum bandwidth in the LTE system according to the following formula (1); and acquiring a remaining capacity in the LTE system according to the following formula (2);

 For the GSM system, the equivalent spectral bandwidth in GSM is obtained according to the following formula (3); and the remaining capacity in the GSM system is obtained according to the following formula (4);

For the WCDMA system, obtaining a WCDMA system according to the following formula (5) Equivalent spectral bandwidth; and obtaining the remaining capacitance in the WCDMA system according to the following formula (6)

Formula α)

j _{2 = f} f ₂ - v ₁ .e ₁ -N ₂ .e ₂ -N3-e ₃ -N ₄ -e _4f Equation (2) where, represents the preset subcarrier bandwidth, indicating the preset ^φ , class Business activation factor,

C represents the total number of subcarriers preset in the LTE system, ?, „ indicates the preset ^φ , the rate of the “user” in the class service;

^ denotes the measured ^Φ , the channel gain of the "user" on the first subcarrier in the class service, σ ² represents the measured noise power, ^ represents the acquired ^Φ , the average power of the user in the class service (can be passed under The formula derivation, see description below), c '" indicates the allocation of the calculation acquisition

^Φ , the number of subcarriers of the "users in the class", ", is the coefficient, «^-1-5 10^5^).

 ^ indicates the system capacity preset in the LTE system. This value is determined by the operator when establishing the network.

^{Ν Ν Ν} indicates the number of users of the session type service, the interaction type service, the flow type service, and the background type service in the LTE system, respectively, ^δ ι, ^δ2 , and ^{d δ4} represent the session type service and the interaction type service in the LTE system, respectively. The equivalent bandwidth of the streaming and background services.

It should be noted that ^, ", C, ? _{∞ in the} above formula (1) and formula (2) are system parameters designed when the LTE system is established; G _yn and σ ² are measured by the terminal and/or the base station. Parameters.

= ^Ζ constitutional formula (3)

 ^ = ^0 -^ formula (4)

Where ^ represents the equivalent spectral bandwidth of the session class service in the GSM system. Indicates preset The total spectrum bandwidth preset in the GSM system, indicating the number of users who already have session-type services in the GSM system;

Specifically, the above parameters. It is determined by the operator when establishing the GSM system. Equation ( 5 ) ' = ^9.5kHz , d ₄ = 60.2kHz

Formula (6) ϋ · ^δ ιΚ _ ₄ · δ ₄

Where ^ represents the total spectrum bandwidth preset in the WCDMA system. This value is determined by the operator when establishing the network, usually 5MHz. NN ₂ and N ₄ respectively indicate that there are already session-type services and interactive services in the WCDMA system. And the number of users of the background type service, d δ ₂ , respectively represent the equivalent spectrum bandwidth of the session type service, the interaction type service, and the background type service in the WCDMA system.

 The above network switching method considers the remaining capacity of each network in the heterogeneous network on the one hand; on the other hand, considers the types of services that the network can support, for example, classifying the network according to the types of services that the network can support, for a specific service. When selecting a network, try to access a network that is accessible to the service and has poor network applicability, so that network resource allocation is reasonable, network resource utilization is improved, and the call blocking rate of the service is reduced.

 The GSM system is taken as an example to describe in detail the derivation process of the equivalent spectral bandwidth and residual capacity calculation formula in the GSM system.

 In the GSM system, a number of cells (3, 4 or 7) form a block, the same channel cannot be used in the group, the same channel distance remains equal, and each cell contains multiple carrier frequencies, each carrying There are 8 time slots in the frequency, that is, there are 8 physical channels per carrier frequency (that is, the actual channel for wireless signal transmission). Therefore, the GSM system is a time division multiple access (TDMA) access method and The access method of Frequency Division Multiple Access (FDMA) is shown in Figure 4.

For TDMA systems (systems with TDMA access) and FDMA systems (for FDMA access), TDMA frames on one carrier have 8 slots, one slot Called a physical channel. Each carrier frequency is defined as a TDMA frame, which is equivalent to one channel of the FDMA system. In the GSM system, the equivalent bandwidth of each carrier frequency is 200KHZ, and each carrier frequency contains 8 time slots, then the equivalent bandwidth of each time slot is ^^ = ₂₅ 3⁄4.

 8

 The GSM system is a circuit-switched system in which each user can only use one time slot in one TDMA frame, that is, each user has an equivalent bandwidth of 25 kHz. It should be noted that since the GSM system is mainly applicable to session-type services, the above equivalent bandwidth can be understood as the equivalent bandwidth of a user's session-type service in the GSM system.

 That is to say, the services that the GSM system can provide are divided into basic communication services and supplementary services. The supplementary services are only the expansion of basic services. They cannot be provided to users separately. These supplementary services are not dedicated to the GSM system, and most supplementary services are It is inherited from the fixed network and the supplementary services that can be provided. Therefore, the communication service in the GSM system is mainly the session type service.

Further, the number of users representing the services in the GSM system is set, and the sum of the equivalent spectrum bandwidths occupied by the users of the service type cannot exceed the total spectrum bandwidth ^{w of the} GSM system. . The following inequality:

 Therefore, the equivalent spectrum bandwidth of the session-type service is 25ΚΗζ.

The remaining capacity of the GSM system is: Χ ₀ =^ ₀ Κ

Where w ₀ represents the system capacity preset in the GSM system (the value of this is determined by the operator when establishing the system network), indicating the number of users who already have session-type services in the GSM system, and ^ indicates the session class in the GSM system. The equivalent spectral bandwidth of the service.

Of course, since the GSM system cannot be applied to the interactive type service, the background type service, and the stream type service, in the GSM system, the values of S ₂ and S ₃ are both 0.

The following takes the LTE system as an example for detailed description. The equivalent spectrum bandwidth and the LTE system. The derivation process of the calculation formula of the remaining capacity.

In this embodiment, an Orthogonal Frequency Division Multiple Access (OFDMA) system is taken as an example to determine that there are a total of C subcarriers in an OFDMA system, and each service type in the OFDMA system. Users have their own fixed power limits. For example: The first user in a service with the service type ^ ^ ¹ , ² , ... is assigned the average power of Α·«.

 The service types in this embodiment include: a session type service, an interaction type service, a background type service, and a flow type service.

Assume that the total number of all users of all service types in the OFDMA system is . Then, the rate that the "users on the subcarriers" in the service type ^φ ' can reach: c _ljn -Wlog ₂ (l ₊ a-^^) _{( )} where "_1. ⁵ /1. _§ ( ⁵ ^) (BER indicates the required bit error rate), indicating the channel gain of the "user on the subcarrier" in the service of the service type. Representing the spectrum bandwidth of a single subcarrier, indicating on a subcarrier Noise power.

 Based on the above formula (1,), the data transmission rate expression of the user whose service type is ^^^, ...^ can be further obtained, that is:

R. = CW log ₂ (1 + · ^β '»' ^ρ '»' ^η ')

^{2 1} o -C _m ( = 1,2,..Χ 2, ,) _{( 2} ') In the formula (2'), the user rate indicates the first business in the business type ^ ^ ¹ , ² ,... " = i, the rate of ² N activated users; the number of users activated in the service of the service type; which indicates the number of subcarriers of the "user" allocated to a service of type ^Φ , ^{α <·} ^ indicates the service type of service required for the bit error rate, ^ is allocated to the service type ^Φ <the first business "average power user, the service type is a ^ ^Φ <business Activation factor. Wherein, the user rate, ^ is a predetermined value.

^G , «represents the average channel gain of the "user" in a service with a service type of ^Φ , · ^G , " can be expressed as follows:

1 ^c ,

 ( = 1,2,...,^« = 1,2,...N,.) In order to use the concept of "equivalent spectrum bandwidth" to express QoS requirements for different service types (eg: bit error rate limitation) As well as the user rate requirements), the above formula (2') needs to be further derived.

Combined with the following Lagrangian series extended expression (3'), log ₇ (l + ) =—— + + ...

² In 2 21n2 31n2 ( 3' ) According to the formula (3'), the formula (2') is deformed to obtain the following formula (4'). First, you can use the Lagrangian series expansion formula ( 3 ' ) to express the expression log ₂ (l + a, -3⁄4^)

σ expands into the following form:

Using the result of (4'), the above formula (2') can be reconstructed as: ln2 a ² , 21η2 a ⁴ C ^J (5')

( = 1,2,...,^« = 1,2,...N,.) Further deforming the (5') formula, you can get:

R. a GP η h. a ^z GP η 1 ^ζ

W 1η2·σ ² 21n2-a ⁴ - (6,) (7,)

(8,)

Wa- G _m P _{in i}

(9,) replace the random variable in equation (9') with the expression already obtained, ie

At this point, you can get an expression for the number of subcarriers allocated to the "user" of a service with a service type of ^φ <:

 ( = 1,2,...,^« = 1,2,...N,.)

It can be known from the formula (10,) that when the QoS requirement (bit error rate ^α ' and user rate ^ ) of a certain type of service ^('' ^{= 1} , ² , ' ) is given, it can be calculated that it should be assigned to this The number of subcarriers c _∞ of the user " = 1, ² , Ά ·) in the service type. Set ( = i, 2, ..., k) as a time slot in the OFDMA system The number of users whose service type is Φ = ΐ, ² , . . . represents the total spectrum bandwidth of the entire OFDMA system.

 In practical applications, the sum of the spectrum bandwidth occupied by all activated users in a time slot in the entire OFDMA system cannot exceed the total spectrum bandwidth of the OFDMA system. The following inequality (11,):

VVC

'=ι «=i (11 ) The ^c in the inequality has the same meaning as above, that is, the number of subcarriers in the OFDMA system, and its relationship with the total spectrum bandwidth of the OFDMA system is:

Cw = w ₃ (12,) If the left and right ends of the inequality (11') are multiplied by ^ at the same time, it can become: ∑∑c _m w≤cw

 w " (13,) Replace ^ and ^^ in the above equation with and , and inequality (13,) can be simplified as follows:

 k N:

∑∑s _m <w ₃

(14,) where ( = 1'2'·Ά" = 1,2,·Ά) is defined as a business type of Φ, ( = 1'2'... in the business of the first "(" ⁼¹ , ² , ...) The equivalent spectral bandwidth occupied by a user, the expression of which is as follows:

H (15,) Substituting the expression in the above equation (10') with the expression in the above equation, you can get:

(16') The formula (16') is the above formula (1).

 The meaning of the relevant parameters in the formula (16') is consistent with the meaning of the relevant parameters in the above formula (1), and will not be further explained here.

Thus, through the mapping of (16'), the different QoS requirements of the user (including the user's bit error rate requirement ^α ' and rate requirement) are equivalent to the different bandwidth resource requirements ^δ '« required by the user. Therefore, the network switching device (such as the base station) can perform subcarrier allocation on the medium access control layer (MAC) level according to the bandwidth requirement of each user to meet the transmission quality requirement. For a certain type of service ⁰ <('' ^{= 1} , ² , "^), the foregoing has assumed that the number of users belonging to this type of service and activated in a certain time slot has ( ^{= 1} , ² , , ) Then, since these users belonging to the same type of service each occupy the required equivalent spectrum bandwidth when activated, it is possible to further obtain this type of service ⁰ '( ^{= 1} , ² , '" occupying the OFDMA system. The number of bandwidths (the number of bandwidths there is the equivalent spectrum bandwidth of all users of a certain type of service):

 (i = l, 2, -, k)

 By allocating different types of services to their respective required equivalent spectrum bandwidths, an OFDMA system with multiple services access can be seen as a system that guarantees both QoS requirements.

 According to the foregoing algorithm, the equivalent spectrum bandwidth of the session type service, the interaction type service, the flow type service, and the background service in the LTE system can be calculated.

 According to equation (16), it can be known that, in the case where the bit error rate is constant, the equivalent spectral bandwidth of each type of service is only related to the average power ^. So what kind of relationship exists between them?

 For this reason, since the above average power is given as a range, not a certain value, and different average powers, different equivalent spectrum bandwidths are caused.

 For an OFDMA system, the smaller the equivalent spectrum bandwidth occupied by the user, the more users the OFDMA system can carry, the better the OFDMA system. At this time, an optimal average power can be calculated, so that the user's equivalent spectrum The bandwidth is minimal.

Since ^ in the above formula (1, 6) indicates the obtained ^φ , the average power of the user in the class service, how to obtain the best average power can be seen as follows.

When the subcarrier bandwidth = ⁵ o ^ fe, the number of subcarriers C = 100, the error rate SE? = 10- ^3, the noise power ^{σ 2} = \ 0 η Ψ, ^ is the channel gain set to ^10-10 and the center variance of less than ^10-3. The activation factor of the session-type service is ⁼⁰ · ⁶ , the rate of the session-type service = ¹⁶ ^^; the activation factor of the interaction-type service is ⁷⁷ '= ⁰ · ³ , the rate of the interactive-type service = ⁶⁴ ^^; the activation factor of the flow-type service "': ¹ , rate of streaming service = ⁶⁴ ^^; activation factor of background type service ^{= 0} ' ² , rate of background type service = ⁶⁴ ^^ ⁵ .

 In the case of subcarrier bandwidth, number of subcarriers, bit error rate, noise power, channel gain, activation factor of various services, and rate of various services, the equivalent of various services can be obtained according to equation (16). The relationship between bandwidth and average power is shown in Figure 5A, Figure 5B, Figure 5C, Figure 5D.

 As can be seen from FIG. 5A, FIG. 5B, FIG. 5C, and FIG. 5D, in the case where other variables are constant, various services vary with the average power, but there is an optimal average power, and the equivalent spectrum bandwidth is the smallest. Take up the least resources. The best average power for each type of service and the equivalent bandwidth at this power are determined by the following calculations.

 In order to find the best average power, the equation (16') is first derived:

 Second, let =o, find the best average power is:

-_ 2\n2CR _in a ²

(19,) Then, substituting equation (19') into equation (16') simplifies the optimal equivalent bandwidth:

 δ,.„ =2 In 2 feet.,

(20,) Calculate the best average power of each type of service and the equivalent bandwidth at this power limit from equations (19') and (20'): The best average power of the session type service is ^{= ()l} , The best equivalent bandwidth is d. = 22.2KHz The best average power of the interactive class service is: ⁰ ' ⁰⁹ , the optimal equivalent bandwidth is

d _in = ^.lKHz The best average power of the stream class service is ^{= ()27} , and the optimal equivalent bandwidth is

d _in = ^.lKHz The best average power for background traffic is ^{= ()} · ¹³⁷ , the optimal equivalent bandwidth is d _; ^ KHz

In addition, in step 102 shown in FIG. 2 and step 302 shown in FIG. 3, it is determined that: according to the identifier of the current service of the terminal, the service feature of the current service of the terminal is determined, and two or more networks matching the service feature are selected. .

 Specifically, the service feature-based network selection algorithm is illustrated as follows, which is used to determine whether to allow services to access the network according to the service characteristics and the relative remaining bandwidth of the network.

 Service characteristics refer to different types of services that can be accessed by various types of services. As shown in Figure 6, for example, session services can be connected to GSM systems, WCDMA systems, and LTE systems. This is called access capability, and interactive services can be connected. In the WCDMA system and the LTE system, the streaming service can access the LTE system, which is called poor access capability, and the background service can access the WCDMA system and the LTE system. Therefore, the GSM system has the most single bearer service and is only suitable for accessing the session type service. It is called the network applicability is poor. The four services in the LTE system can be carried, which is called network applicability.

 In order to classify the network and classify the network, the definition ^ indicates the applicability of the network, that is, the ability of the network to allow access to the type of service. If the applicability of the network is worse, the priority of the network being selected is higher, and conversely, the lower the priority of the network being selected. That is, as long as the business allows, first select the network with poor capability, and select the high-end network for the demanding business.

T ^J

R ^J =―

τ ( 21,) Where RAT j represents the wireless access technology of the j network/system, because the access technologies of different networks are different, so the RAT j can be used to represent the j network/system;

 ^ indicates the number of service types that the j network/system can access;

 2 " indicates the total number of business types;

 ^ indicates the ratio of the number of service types that the j network/system can access to the total number of service types. The larger the value, the better the applicability of the RAT j network, and the lower the priority of the network is selected; otherwise, the RAT j The poorer the applicability of the network, the higher the priority of the network being selected.

 Thus, according to the above formula (21 '), the value of ^ of the GSM system, the WCDMA system, and the LTE system can be calculated, indicating the applicability of the network, and the larger the ^, the stronger the applicability. As shown in Table 1 below:

 Table 1

In addition, the control condition of another access network is the relative remaining capacity of the network (the ratio of the remaining capacity of the network to the total spectrum bandwidth of the network), and the remaining capacity of the network is greater than or equal to that required for the type of service in the RAT j network. When using the spectrum bandwidth, you should try to choose a network with a relatively large remaining capacity of the network.

That is to say, firstly, according to the service characteristics, select the network that ^φ , the class service can access (for example, the session type service can access any network, and the flow service is only suitable for accessing the LTE system, etc.); secondly, judge the remaining of these networks. Whether the capacity is greater than or equal to the equivalent bandwidth required by the service in the network. If ^≥ , it can be accessed. Otherwise, the access is denied. Finally, in a network that meets the above conditions, a network with poor applicability and relatively large remaining capacity is selected.

In order to express the above conditions by mathematical formula, define M/, for ^Φ , class service, Μ/ combines two indicators of remaining capacity and business characteristics, which are their weighted values, and select the appropriate network with Μ/. .

For a heterogeneous network consisting of a GSM system, a WCDMA system, and an LTE system, it is assumed that '' = 1 indicates a session-type service, ''= ² indicates an interactive service, ''= ³ indicates a flow service, and ''= ⁴ indicates a background. Class service; = 1 indicates GSM system, = 2 indicates WCDMA system, and =3 indicates _L TE system. According to the adaptability of the service and the network (as shown in Figure 6 above), the values for different networks are different, for example: _ζ · _{= 3} , 7' = 3; = 1, = ^2, 3, 4. Then, the conditions that the Φ service needs to access the RAT j network are:

w _f -z ^J

Minimize M ^J = R ^J + a ~

^W J

(22,) st (i, j) e { (1, 1), (1, 2), (1, 3), (2, 2), (2, 3), (3,3), (4 , 2), (4, 3)} d < χ ³ st indicates the condition, that is, the condition in st must be satisfied when selecting ^Μ 'the smallest network.

 Where ^ represents the remaining capacity of the RAT j network;

Represents the equivalent spectral bandwidth of ^φ , class service in the RATj network.

 ^ represents the total spectrum bandwidth of the system of the RATj network;

 « is a constant that reflects the weight of the two factors of the service characteristics and relative residual capacity in the network selection, which can be determined by the operator.

In equation (22,), condition one: ( {(1,1),(1,2),(1,3),(2,2),(2,3),(3,3),(4 , 2), (4, 3)} reflects the correspondence between ^Φ < class service and RATj network, for example, session ( =1 ) can access any network Network (j can take any value), and the stream is only suitable for access to LTE systems, etc.;

Condition 2: ^≤ Reactive network has enough remaining capacity to carry the service; then, based on these two necessary conditions, select a network with poor applicability and relatively large remaining capacity.

 The above method of network handover indicates that the network j selected by the service is an optimal network selected by combining two factors of remaining capacity and service characteristics.

 In practical applications, it can be proved by simulation that the above method is achievable, and whether the target network is the most suitable target network.

Specifically, if one time slot is set to one unit time, and the time slot number is ^: ⁰ , ¹ , ² , ..., then the arrival rate ^A '( ^{= 1} , ² , ³ , ⁴ ) is expressed in one time slot. The number of users of the arriving ^φ <· class service, the departure rate ^( ^{= 1} , ² , ³ , ^4; ' ^{= 1} , ² , ³ ) indicates the user of the ^φ 'class service leaving the RATj network in one time slot number. At the same time, it is assumed that the user's arrival obeys the Poisson distribution, and the user's departure obeys the binomial distribution. Where = 1 means session-type service, = 2 means interactive class service, = 3 means flow class service and = 4 background type service, · = 1 means GSM system, · = 2 means WCDMA system and · = 3 means LTE system. If ^ is used to indicate the number of users of the ^ class service already existing in the RATj network

( = 1,2,3,4; ' = 1,2,3 ) , according to Figure 6, the values are different for different networks, for example: = 1 = 1, = 3; = 3, = 1 , 2, 3, 4. Moreover, the number of users of the ^Φ '· class service already existing in the RAT j network is limited by the following formula. i ^{3 3} ( 23,) Equation (23') indicates that the equivalent bandwidth occupied is less than the total bandwidth. Therefore, the state of the time slot of the heterogeneous network composed of the GSM system, the WCDMA system, and the LTE system is: = , ', ) 1,1), (1, 2), (2, 2), (4, 2), (1,3),

 V i

(twenty four,) In time slot ^/, φ arrival, the number of users for the service class RAT j ^[Phi] leave the network, the number of users for the service-class, and are satisfying ^ Poisson and binomial random numbers, wherein, The condition to be satisfied is less than or equal to the number of users of the ^φ , class service already existing in the RATj network, that is, less than. Next, according to the equations (23') and (22'), it is judged whether these arriving users can access the heterogeneous network and determine the target network that the user chooses to access.

 First, it is determined whether these users can access the heterogeneous network. According to equation (22'), as long as one network satisfies condition 1 and condition 2 in equation (22') in the GSM system, the WCDMA system, and the LTE system, Then the user can access, otherwise, the access is denied, a rejection is generated, and the number of times the user blocks is increased by one.

 Secondly, judging the networks that these users choose to access, according to equation (22'), the smallest network is selected. Because various types of services can access different networks, it is necessary to define different judgment functions to determine whether services can access the network.

 The function αΐ determines whether the session type service can access the GSM network, and the function value is 1 to indicate access, and the function value is 0 to indicate that it cannot access;

The function ^β2 ( , ^"^"" , "^" determines whether the session-type service can access the WCDMA system, the function value is 1 to indicate access, and the function value is 0 to indicate that it cannot access;

The function a im^ _l , m _n , m ₂₂ , m ₄₂ , m _u , m ₂₃ , m ₃₃ , m ₄₃ ) determines whether the session class service can be accessed |_Τ E system, the function value is 1 means access, function A value of 0 means no access;

Function ⁰¹ ( ^Wll , ^Wl2 , ^W22 , ^W42 , ^Wl3 , ^W23 , ^W33 , ^W 4 ³ ) determines whether the interactive class (or background class) service can access the WCDMA system. The function value is 1 to indicate access, and the function value is 0. Indicates that access is not possible; function ^{0 11} , " ⁷¹² , ² , ² , " ⁷¹³ , ^{3 33} , ³ ) determines whether the interactive class (or background class) service can access the LTE system, and the function value is 1 to indicate access, function A value of 0 means no access.

 The streaming service can only access the LTE network, so no judgment function is needed.

The expression of the function is as follows: l(

 o other

(25') dl(m _x ,m _u ,m ₂₂ , m ₄₂ ,m _l3 ,m ₂₃ , m ₃₃ , m ₄₃ )

m _n . d _l +m ₂₂ -d ₂ +m. m _l3 . d _x +/3⁄4 . δ ₂ + m ₄₃

1 R ^l + ; min(R ■)

 o other

(26,) a3(m _n , m _n , m ₂₂ , m ₄₂ , m _n , m ₂₃ , m ₃₃ , m ₄₃ )

 o other

(27,) bl(m _n m ₁₂ , m ₂₂ , m ₄₂ , m ₁₃ , m ₂₃ , m ₃₃ , m ₄₃ )

m _l2 . d _l + m ₂₂ . d ₂ + m ₄₂ - d _{4 <} j^> ₊ ^m n ' + ' + m ₄₃ . d ₄

1 R ² +

0 other (28,) b2 (m _u m ₁₂ , m ₂₂ , m ₄₂ , m ₁₃ , m ₂₃ , m ₃₃ , m ₄₃ )

m, ■d ₁ + ff3⁄4 ₃ ·&■ + m ₄₃ · d ₄ + m ₄₂ . d ₄

1 R ³ + ≤R ^Z +

Other 0 (29) according to ^{φ RATj [Phi]} leave the network, number of users and traffic classes heterogeneous network arrives, the number of user-service class ^, the first slot ζ ^ subtracting the state space The number of users leaving, then, by the formula (25') ~ (29') to determine whether the arriving user can access, if it can access, the corresponding ^w "plus the access user, so you can get The time slot / + 1 state, that is, the value of the next time slot. The above process is repeated in the next time slot. This is 5,000 cycles, if the class service is in the 5000 slot length, the total number of arrivals is, the number of times the blocking occurs is The blocking rate of ^Z- like services is: In order to compare with the above network selection formula (22'), the comparison object is a general network selection algorithm based on relative residual capacity, and the formula selected by the network selection algorithm is:

W ^j - r ^j

Minimize N ^J =

W ^J

St ( , ₇ {(1,1),(1,2),(1,3),(2,2),(2,3),(3,3),(4,2),(4, 3)} d{ < _Z ^J _{( 3 )} where st represents the condition to be satisfied, indicating the remaining capacity of the RATj network; representing the equivalent spectrum bandwidth of the 'class service' in the RATj network;

 Indicates the system capacity of the RATj network.

W ⁱ - _X ⁱ

 In (31'), it represents the ratio of resources occupied by users already existing in the network to system resources. The network selected by the network selection algorithm based on the relative remaining capacity is that within the network accessible by the service, the existing users in the network occupy the smallest resources and the remaining resources are sufficient to carry the network of the service.

 In the case of the same arrival rate and departure rate, the call blocking rate of each type of service is based on the network feature selection algorithm based on the service characteristics and the network selection algorithm based on the relative remaining capacity.

 The system capacity of the preset GSM system, WCDMA system, and LTE system are:

W = 6.25MHz, W ₂ =5MHz, W ₃ =5MHz , the equivalent bandwidth of each type of service in each network is: Equivalent bandwidth of session type service in GSM system = ^25j0z , equivalent of session type service in WCDMA system Bandwidth = ^35j£ , equivalent bandwidth for interactive services = ⁸⁹ ' ^5j£ , equivalent bandwidth for background services = ^{6 2 ζ} , equivalent bandwidth for session services in LTE networks = ²² ' ^2j£ , for interactive services The equivalent bandwidth ³³² = ⁸⁸ · ^{7 Ζ} , the equivalent bandwidth of the flow class service = ⁸⁸ · ^{7 Ζ} , the equivalent bandwidth of the background type service = ⁸⁸ · ^{7 Ζ} .

In this case, if = 1⁄2 = 1⁄2 = 1⁄2 = Α ₃ = 1⁄2 = 1⁄2 = 1⁄2 = 0.5 and in order to make various types of business Blocking will occur, and the rate of shell 'J j is especially large enough, let 4 = [20,30, 40,50, 60] , ^ = ^ = ^ = ^

« = 1, the blocking rate of various services under the two network selection algorithms programmed by Matlab, as shown in Figure 7A, Figure 7B, Figure 7C and Figure 7D.

 It can be seen from FIG. 7A to FIG. 7D that, in the case of the same arrival rate and departure, the call blocking rate of various services calculated based on the service feature-based network selection algorithm is calculated compared to the network selection algorithm based on the relative remaining capacity. The blocking rate is small, whereby the network feature selection algorithm based on the traffic characteristics allows more users to access in the case of the same arrival rate and departure rate.

 Therefore, the above formula for selecting a network enables the device to more appropriately allocate resources of the heterogeneous network, improve the utilization of the heterogeneous network resources, and reduce the call blocking rate of the service.

 In particular, the above weights are obtained through experiments.

 It can be seen from the foregoing embodiment that the method for network handover in this embodiment preferably maps time slots in the GSM system to equivalent spectrum bandwidth, maps orthogonal carriers in the LTE system to equivalent spectrum bandwidth, and converts the WCDMA system. The orthogonal code channel mapping in the middle is equivalent to the bandwidth of the spectrum, which is more conducive to the allocation of resources, and the comparison and scheduling of system resources between systems. In the process of realizing the equivalent spectrum bandwidth, not only the load of the network is considered. (relative residual capacity of the network), also considering the business characteristics, based on these two factors to select the network. Therefore, the resource allocation of heterogeneous networks is more reasonable, the utilization of heterogeneous network resources is higher, and the call blocking rate of services is lower.

 According to another aspect of the present invention, the present invention further provides a device for network switching. As shown in FIG. 8, the device for network switching in this embodiment includes: a receiving unit 81, a selecting unit 82, and a target network selecting unit 83. ;

 The receiving unit 81 is configured to receive a network switching request sent by the terminal, where the network switching request includes: an identifier of a current service of the terminal;

 The selecting unit 82 is configured to determine, according to the identifier, a service feature of the current service, and select two or more networks that match the service feature;

The target network selecting unit 83 is configured to select a network with poor applicability and/or a relatively large remaining capacity in the two or more networks as the target network of the terminal handover; The relative remaining capacity is the ratio of the remaining capacity represented by the equivalent spectral bandwidth of each of the two or more networks to the total spectral bandwidth of the network.

 Of course, if the network selected in the selection unit 82 matches the service feature, the target network selection unit 83 is further configured to use the network selected by the selection unit 82 as the target network switched by the terminal.

 Further, as shown in FIG. 9A, the apparatus for network switching shown in FIG. 9A further includes: a sending unit 84, configured to send a network switching response to the terminal, where the network switching response includes the selected The identity of the target network.

 The foregoing service features include: a session type service feature, an interaction class service feature, a stream class service feature, or a background class service feature.

 In an actual application, the device for network switching further includes: an obtaining unit 83a (as shown in FIG. 9B), the acquiring unit 83a is configured to acquire a remaining capacity of each of the two or more networks, and the terminal The equivalent spectrum bandwidth occupied by the current service in the two or more networks.

Specifically, the target network selecting unit 83 is specifically configured to select, according to M ^J = R ^J + a ^J , a network corresponding to the minimum Μ^′ as the terminal cut

^W J

Changed target network;

Among them, belong to {(1,1), (1, 2), (1,3), (2, 2), (2, 3), (3, 3), (4, 2), (4, 3 In the parameter, _Rj represents the preset network applicability parameter, ^ represents the total spectrum bandwidth in the network corresponding to ^, ^ represents the remaining capacity of the network corresponding to ^, "represents the relative remaining capacity and the right of the service feature The constant of the value.

 For example, if the two or more networks include: an LTE system, a GSM system, and a WCDMA system;

 The acquiring unit 83a is specifically used for

For the LTE system, obtaining an equivalent spectrum in an LTE system according to the following formula (1) Bandwidth; and obtaining the remaining capacity in the LTE system according to the following formula (2); for the GSM system, obtaining the equivalent spectrum bandwidth in GSM according to the following formula (3); and acquiring the GSM system according to the following formula (4) Remaining capacity

 For the WCDMA system, the equivalent spectral bandwidth in the WCDMA system is obtained according to the following formula (5); and the remaining capacity in the WCDMA system is obtained according to the following formula (6)

Formula (1) e,.„ - w -

Equation (2) z ₂ = W ₂ - N ₁ 'd ₁ - N ₂ 'd ₂ - N ₃ 'd ₃ - N _{4 -} d ₄ . where W represents the preset subcarrier bandwidth, indicating the preset ^φ The activation factor of the class service, C represents the total number of subcarriers preset in the LTE system, and represents the preset ^φ , the rate of the "user" in the class service;

C ^ denotes the measured Φ, the channel gain of the "user" on the first subcarrier in the class service, σ ² represents the measured noise power, ^ represents the acquired ^Φ , the "average user average power" in the class service, represents the calculation The number of subcarriers allocated to ^Φ , the first user in the class service, is the coefficient, a _; «-1.5/log(55Ei?).

^ indicates the system capacity preset in the LTE system. This value is determined by the operator when establishing the network.

^NNN ^ indicates the number of users of the session type service, the interaction type service, the flow type service, and the background type service in the LTE system, respectively. ^δ ι, ^δ2 , and ^d respectively represent the session type service, the interaction type service, and the flow class in the LTE system. Equivalent bandwidth for business and background services;

 Formula (3) 5; - 25kHz

Formula (4) ζ ₀ = ₀ Κ

Where ^δ ι represents the equivalent spectral bandwidth of the session-type service in the GSM system. Express GSM The total spectrum bandwidth preset in the system, indicating the number of users who already have session-type services in the GSM system;

Equation ( 5 ) d _l - 35kHz , d ₂ = 89.5kHz , δ ₄ = 60.2kHz Equation (6)

- N df N d ₄ where ^ represents the total spectral bandwidth in the system preset in the WCDMA system, NN ₂ ,

N ₄ denotes the number of users of the session type service, the interactive type service, and the background type service, respectively, in the WCDMA system, and d δ ₂ , which respectively represent the equivalent spectrum bandwidth of the session type service, the interactive type service, and the background type service in the WCDMA system. .

 It can be seen from the above embodiments that the device for network switching in this embodiment can make the resource allocation of the heterogeneous network more reasonable, the utilization of the heterogeneous network resources is higher, and the call blocking rate of the service is lower.

 In addition, it should be noted that the device for network switching may include a processor and a memory, where the functions implemented by the processor may be functions implemented by the receiving unit 81, the selecting unit 82, and the target network selecting unit 83. Further, The processor is also used to implement the functions implemented by the transmitting unit 84 and the obtaining unit 83a described above.

 The above memory can be used to store the above formula (1) to formula (6), and in the processing of the processor, the processor can respectively acquire the remaining in each network according to formulas (1) to (6) in the memory. The capacity and the equivalent bandwidth, and the processor, after receiving the network switching request sent by the terminal, determining the service feature of the current service according to the identifier, and selecting two or more networks that match the service feature; Networks with poor applicability, and/or relatively large remaining capacity in more than one network serve as the target network for the terminal handover.

 According to still another aspect of the present invention, the present invention further provides a base station, which may include the apparatus for network switching described in any of the embodiments of the present invention. The device for network switching can implement the network switching method described in any of the above embodiments.

 According to a fourth aspect of the present invention, the present invention further provides a base station controller, which may include a network switching apparatus according to any of the embodiments of the present invention, where the network switching apparatus may implement any of the foregoing embodiments. The network switching method described.

It can be understood that the device for network switching mentioned above may be a device newly added in an existing network, or may be a functional module integrated in an existing device in an existing network, for example, integrated in a multimode base station controller. Device in ( Multi-Mode Base Station Controller ). It will be understood by those skilled in the art that all or part of the steps of implementing the above method embodiments may be performed by hardware related to the program instructions. The aforementioned program can be stored in a computer readable storage medium. When the program is executed, the steps including the foregoing method embodiments are performed; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

 It should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

Claim

 A method for network switching, comprising:

 Receiving a network handover request sent by the terminal, where the network handover request includes: an identifier of the current service of the terminal;

 Determining, according to the identifier, a service feature of the current service, and selecting two or more networks that match the service feature;

 Selecting, in the two or more networks, a network with poor applicability and/or a relatively large remaining capacity as a target network for the terminal handover; the relative remaining capacity is equivalent to each of the two or more networks. The ratio of the remaining capacity represented by the spectrum bandwidth to the total spectrum bandwidth of the network.

 2. The method according to claim 1, further comprising:

 If the network matching the service feature is selected as one, the selected network is used as the target network switched by the terminal.

 The method according to claim 1 or 2, further comprising: sending a network handover response to the terminal, where the network handover response includes an identifier of the selected target network.

 4. The method according to any one of claims 1 to 3, characterized in that the service features comprise:

 Session-type business characteristics, interaction-type business characteristics, flow-type business characteristics, or background-type business characteristics.

The method according to any one of claims 1 to 4, wherein the selecting a network with poor applicability and/or a relatively large remaining capacity in the two or more networks as a target network for the terminal handover Before the steps, it also includes:

 Obtaining a remaining capacity of each of the two or more networks and an equivalent spectrum bandwidth respectively occupied by the current service of the terminal in the two or more networks.

The method according to claim 5, wherein the selecting a network with poor applicability and/or a relatively large remaining capacity in the two or more networks is used as the destination of the terminal handover. The process of the standard network, including:

M = R + a- according to , selecting the network corresponding to the minimum Μ / ' as the target network of the terminal switching;

 Where: · belongs to the parameter in ("^{(UM WUWWWWW)}, ^ represents the preset network applicability parameter, ^ represents the total spectrum bandwidth in the network corresponding to ^, and represents the remaining capacity of the corresponding network," A constant that represents the weight of the relative remaining capacity and business characteristics.

 7. The method according to claim 5, wherein the two or more networks comprise: an LTE system, a GSM system, and a WCDMA system;

 Obtaining, for the LTE system, an equivalent spectrum bandwidth in the LTE system according to the following formula (1); and acquiring a remaining capacity in the LTE system according to the following formula (2); Equation (3) acquires an equivalent spectral bandwidth in the GSM; and acquires a remaining capacity in the GSM system according to the following formula (4);

 For the WCDMA system, the equivalent spectral bandwidth in the WCDMA system is obtained according to the following formula (5); and the remaining capacity in the WCDMA system is obtained according to the following formula (6);

Formula 1 )

Formula (2) Z ₂ = W ₂ -N d, -N ₂ -d ₂ -N ₃ 'd ₃ -N ₄ -d ₄ _ where represents the preset subcarrier bandwidth, indicating the preset ^φ , class service Activation factor, C represents the total number of subcarriers preset in the LTE system, indicating the preset ^Φ , the rate of the "user" in the class service; C ^ denotes the measured ^Φ , the channel gain of the "user" on the first subcarrier in the class service, σ ² represents the measured noise power, ^ represents the acquired ^Φ , the "average user average power" in the class service, represents the calculation The number of subcarriers allocated to the ^Φ , the wth user in the class service is a coefficient, 1.5/log (5SE?). 2 indicates the system capacity preset in the LTE system, and ^N \ and ^NN respectively represent The number of users of the session type service, the interaction type service, the flow type service, and the background type service in the LTE system, and ^δ ι, ^δ2 , and ^d respectively represent the session type service, the interaction type service, the flow type service, and the LTE system, respectively. Equivalent bandwidth of the background service;

Formula (3) ^ = ^25kHz ;

Equation (4) ^ = -Ν^ _{1 ;} where ^δ ι denotes the equivalent spectral bandwidth of the session class service in the GSM system. Representing the total spectrum bandwidth preset in the GSM system, indicating the number of users having session-type services in the GSM system;

Equation (5) ^d i = ^35kHz ' ^d 2 = ^-5k z , d ₄ = 60.2kHz . Equation (6) ^{= w} " ^N , ' ^d , _ ^N 2' ^d f ^N ^ ^d ,

Wherein, ^ represents the total spectrum bandwidth preset in the WCDMA system, and N, N ₂ , N represent the number of users having session-type services, interactive-type services, and background-type services in the WCDMA system, dd ₂ , It represents the equivalent spectrum bandwidth of the session type service, the interaction type service, and the background type service in the WCDMA system, respectively.

 8. A device for network switching, comprising:

 a receiving unit, configured to receive a network switching request sent by the terminal, where the network switching request includes: an identifier of a current service of the terminal;

a selecting unit, configured to determine, according to the identifier, a service feature of the current service, and select two or more networks that match the service feature; a target network selection unit, configured to select a network with poor applicability and/or a relatively large remaining capacity in the two or more networks as a target network for the terminal handover;

 The relative remaining capacity is the ratio of the remaining capacity represented by the equivalent spectral bandwidth of each of the two or more networks to the total spectral bandwidth of the network.

 9. The apparatus according to claim 8, wherein if the network selected in the selection unit that matches the service feature is one, the target network selection unit,

The device according to claim 8 or 9, further comprising: a sending unit, configured to send a network switching response to the terminal, where the network switching response includes an identifier of the selected target network.

 1 1. The device according to any one of claims 8 to 10, wherein the service features comprise:

 Session-type business characteristics, interaction-type business characteristics, flow-type business characteristics, or background-type business characteristics.

The device according to any one of claims 8 to 11, further comprising: an acquiring unit, configured to acquire a remaining capacity of each of the two or more networks, and a current service of the terminal The equivalent spectral bandwidth occupied by the two or more networks respectively.

 The device according to claim 12, wherein the target network selection unit is specifically used for

W - Y ^j

M{ = R ^j + a ¹

According to ^W j , the network corresponding to the minimum Μ/′ is selected as the target network for the terminal handover;

Among them, belong to ( ) e {(l, l), (l, 2), (l,3), (2, 2), (2,3), (3,3), (4, 2), ( 4,3)} parameters, _Rj represents the preset network applicability parameter, ^ represents the total spectrum bandwidth in the network corresponding to ^, ^ represents the remaining capacity of the network corresponding to R ^j , "represents the relative remaining capacity and A constant for the weight of a business feature.

14. The device according to claim 12, wherein if the two are connected to the Internet The network includes: LTE system, GSM system and WCDMA system;

 贝' J, the obtaining unit is specifically used for

 Obtaining, for the LTE system, an equivalent spectrum bandwidth in the LTE system according to the following formula (1); and acquiring a remaining capacity in the LTE system according to the following formula (2); Equation (3) acquires an equivalent spectral bandwidth in the GSM; and acquires a remaining capacity in the GSM system according to the following formula (4);

 For the WCDMA system, the equivalent spectral bandwidth in the WCDMA system is obtained according to the following formula (5); and the remaining capacity in the WCDMA system is obtained according to the following formula (6);

Formula 1 )

Equation (2) 2 = W ₂ - N d _l - N ₂ 'd ₂ - N ₃ 'd ₃ - N ₄ 'd ₄ ^ where represents the preset subcarrier bandwidth, indicating the preset ^φ , class service Activation factor, C indicates the total number of subcarriers preset in the LTE system, ?, „ indicates the preset ^φ , the rate of the “user” in the class service;

^ denotes the measured Φ, the channel gain of the "user" on the first subcarrier in the class service, σ ² represents the measured noise power, ^ represents the acquired ^Φ , the "average user average power" in the class service, indicating the calculation acquisition The number of subcarriers allocated to ^Φ , the first user in the class service, is the coefficient, ^«-1.5/^(55^).

^ indicates the system capacity preset in the LTE system, and the ^NNN indicates the number of users having the session type service, the interactive type service, the flow type service, and the background type service in the LTE system, respectively, ^δ ι, ^δ2 , and ^d respectively Indicates an equivalent bandwidth of a session type service, an interaction type service, a flow type service, and a background type service in the LTE system; Equation (3) ^e i = ^25kHz ;

Equation (4) ^ = -Ν^ _{1 ;} where ^δ ι denotes the equivalent spectral bandwidth of the session class service in the GSM system. Representing the total spectrum bandwidth preset in the GSM system, indicating the number of users having session-type services in the GSM system; Equation (5) ^d i = ^{35 kHz} ' ^d 2 = ^9.5 kHz , d ₄ = 60.2 kHz

Formula (6) X ^{= W} " ^N ' ^d _ ^N 2' ^d 2_N ₄ 'd ₄ where ^ denotes the total spectrum bandwidth preset in the WCDMA system, N, N ₂ , N are indicated in the WCDMA system The number of users of the session type service, the interaction type service, and the background type service, dd ₂ , respectively represent the equivalent spectrum bandwidth of the session type service, the interactive type service, and the background type service in the WCDMA system.

 A base station, comprising: the apparatus for network switching according to any one of claims 8 to 14.

A base station controller, comprising: the apparatus for network switching according to any one of claims 8 to 14.