WO2009009993A1

WO2009009993A1 - A network selecting method, communication system and mobile terminal

Info

Publication number: WO2009009993A1
Application number: PCT/CN2008/071598
Authority: WO
Inventors: Junxiang Guo
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-07-13
Filing date: 2008-07-10
Publication date: 2009-01-22
Also published as: CN101345981A; CN101345981B

Abstract

A network selecting method, communication system and mobile terminal are provided, they belong to communication field. In order to solve the problem that the terminal can not handover among of the networks of different access technique in the prior art, the solutions which is provided by the embodiments of the present invention are: the network selection method includes: obtaining the information of the surrounding networks, the surrounding networks include different access technique types networks; generating a network list according to the information of the surrounding networks; scanning the networks in the network list, obtaining the signal quality information of the scanned network; selecting the network in the network list to attach according to the network list and the signal quality information of the scanned network. A mobile terminal and communication system are also provided. It can be realized that the mobile terminal selects the appropriate network to attach among of the many of the access technique networks by using the technique solutions provided by embodiments of the present invention.

Description

Network selection method, communication system and mobile terminal

The embodiments of the present invention relate to the field of communications, and in particular, to techniques for network selection in the case where multiple access technology types coexist.

Background technique

Under the existing wireless communication technology, mobile users cannot roam and switch under different radio access technologies. In order to solve the problem of roaming handover between mobile users in different access technology types, IEEE ( The Institute of Electrical and Electronics Engineers, Institute of Electrical and Electronics Engineers, established the IEEE 802 Switching Study Group, which has been formally named the IEEE 802.21 Working Group and is responsible for the development of a common switching framework for wired and wireless IEEE 802 standards. (such as IEEE 802.3, IEEE 802.il, and IEEE 802.16) and the 3G standard, which stipulate the requirements for switching between different access technologies and the corresponding switching mechanisms.

With the evolution of wireless communication technologies, terminals and networks, such as base stations and access points, may be multi-mode, that is, support different wireless standards, and sometimes voice and data transmission can be simultaneously performed on multiple interfaces. Today's mobile communication networks have evolved into micro-cellular (such as IEEE 802.11 and IEEE 802.15) and macro-cellular (such as 3rd Generation Partnership Project 3GPP, 3GPP2 and IEEE 802.16), which will create cross-over coverage, handover and network between these cells. The choices will occur between different types of networks.

The media-independent switching solution specified in IEEE802.21 configures some switching function sets in the mobility management protocol stack of the network element, thus forming a new protocol layer called Media Independent Handover (MIH). Switching) Protocol layer, referred to as MIH layer. The MIH layer provides the following services:

1. MIH Event Service (MIH-ES): Provides event classification, event filtering, and event reporting of dynamically changing events on link characteristics, link status, and link quality.

2. MIH Command Service (MIH-CS): Provides MIH user management and control with handover and mobility Off link behavior.

3. MIH Information Service (MIH-IS): Provides detailed information on the characteristics and services of the service network and surrounding networks. This information is used for effective system access and handover decisions.

At present, the main purpose of the MIH layer is to use media-independent switching functions. The MIH layer provides media-independent switching functions through event services, command services, and information services. This independence is achieved through the underlying protocol pairs in the mobility management protocol stack. The upper layer protocol provides a unified interface implementation. MIH's information service mechanism provides a means to learn the detailed information of neighboring networks. MIH information services enable terminals to know the detailed characteristics of their surrounding networks, such as network type, network operator, network service provider, and high-level services that the network can provide. QoS (Quality of Service) characteristics, cost, data rate, security, or geographic location of the access network. That is to say, MIH's information service mechanism provides more policy information for users to choose the network.

The current network selection technology is a mechanism defined by each access medium. The principle of network selection is usually relatively simple, and cannot be adapted to better select the access network under the network coexistence environment of multiple wireless access technologies.

For example, in the existing 3GPP technology, the network selection of the UE (User Equipment) before entering the network is performed according to the following principles and sequences:

(1) Home Public Land Mobile Network (HPLMN) operators and users distinguish the priority of the network through a combined list of public land mobile network PLMNs and Radio Access Technologies (RAT);

(2) After the UE is powered on, it first searches for and selects the last registered PLMN (RPLMN);

(3) If the RPLMN does not exist, look for and select HPLMN or the highest priority

EHPLMN );

(4) If the HPLMN or the EHPLMN does not exist, the user-controlled prioritized PLMNs and the RAT combination list stored in the SIM (Subscriber Identity Module) card are sequentially selected; (5) if the network in the PLMNs and RAT combination list sorted by the user control does not exist, the network in the PLMNs and RAT combination list of the operator-controlled prioritized order saved in the SIM card is sequentially selected;

(6) If the network in the prioritized PLMNs and RAT combination list controlled by the above operator does not exist, the network with the best signal quality is selected from the other PLMNs and RAT combination list.

After the UE selects the network and registers, if the UE is in the roaming state, it can also reselect and register to the network in the higher priority PLMNs and RAT combination list.

In the existing 3G technology, when the signal quality changes and the communication requirements are not met, the network reselection is generally performed, and the principle and sequence of network reselection are the same as above.

In the process of implementing the present invention, the inventors have found that the above-mentioned prior art sets the rules for network selection and network reselection relatively simply, and simply sets the priority of the PLMN and RAT combination list in the SIM card of the user. Then the user selects the network according to the priority level and the signal quality, and the selected network is only limited to the network of 3GPP standard specifications such as GSM, GPRS, 3G. With the emergence of a variety of wireless technologies, such as WiMAX (Worldwide Interoperability for Microwave Access), WiFi (Wireless Fidelity, wireless high-fidelity) and other access technologies, and IEEE802.21 to optimize the network selection mechanism With the advent of technology, the above prior art does not consider how users can perform network selection or network reselection between these networks in the case of coexistence of multiple wireless technology types of networks. The current IEEE 802.21 technology only defines the process of network discovery and dynamic negotiation of the network during the handover process, and does not solve the problem of how the multimode terminal selects different access technology type networks during the initial network access.

In the existing WiMAX NWG standard, the method for network selection in the initial network access situation of the MS (Mobile Station) (ie, the information that the network access provider NAP and the network service provider NSP are not stored in the MS) is as follows:

(1) The MS detects one or more available WiMAX NAPs;

(2) The MS discovers available NSPs associated with one or more WiMAX NAPs; (3) The MS identifies all accessible NSPs in the available NSPs and selects NAPs and NSPs based on some priority criteria;

(4) The MS performs a process of accessing the NAP;

(5) The MS is authorized to register the service and then establish a business relationship with the NSP;

(6) The MS obtains and saves the configuration information.

In the existing WiMAX technology, in the case where the NAP and NSP information are stored in the MS, the MS performs the network selection as follows:

(1) The MS detects one or more available WiMAX NAPs using the saved configuration information;

(2) The MS discovers available NSPs associated with one or more WiMAX NAPs;

(3) The MS identifies all accessible NSPs, uses the saved configuration information and selects NAP and NSP based on some priority criteria;

(4) The MS performs the process of accessing the NAP and establishes the relationship of the access service with the NSP.

In the process of implementing the present invention, the inventor has found that the above-mentioned existing WiMAX technology is based on the principle of simple selection of network selection or network reselection, and generally selects a network according to the NAP signal detected by the user in combination with some priority criteria. Moreover, the selected network is only limited to the WiMAX network, and does not consider the coexistence of multiple types of wireless access technology networks. For example, when 3GPP and WiMAX technologies coexist, how do users choose an optimal network.

Summary of the invention

The embodiments of the present invention provide a network selection method, a mobile terminal, and a communication system, so that the mobile terminal performs network selection or reselection in the case where multiple access technology type networks coexist.

In order to achieve the object of the present invention, an embodiment of the present invention provides a network selection method, the method includes: acquiring information about a surrounding network, where the surrounding network is a network of different access technology types; generating according to information of the surrounding network a network list; scanning a network in the network list to obtain signal quality information of the scanned network; and selecting a network to attach in the network list according to the network list and signal quality information of the scanned network.

An embodiment of the present invention further provides a mobile terminal, where the terminal includes: a network information acquiring unit, Information for obtaining a surrounding network, the surrounding network is a network of different access technology types; a network list generating unit, configured to generate a network list according to information of the surrounding network; and a scanning unit, configured to scan the network list a network, obtaining signal quality information of the scanned network; and a network selection unit, configured to select a network in the network list for attachment according to the network list and signal quality information of the scanned network.

The embodiment of the present invention further provides a communication system, where the communication system includes: a mobile terminal, configured to acquire information about a surrounding network, generate a network list according to the information of the surrounding network, scan a network in the network list, and obtain a network. Scanning signal quality information of the network, selecting a network to be attached in the network list according to the network list and signal quality information of the scanned network; and a media independent information server for storing and providing the surrounding network Information; The surrounding networks are networks of different access technology types.

The foregoing technical solution provided by the embodiment of the present invention obtains a network list by acquiring information of a surrounding network, and then generates a network list according to information of the surrounding network, and then scans the network in the network list, and finally performs network selection according to the network signal quality information and the network list obtained by the scanning. The mobile terminal can be selected to select an appropriate network to connect between networks of multiple access technology types.

DRAWINGS

1 is a simplified flowchart of a method according to Embodiment 1 of the present invention;

2 is a simplified flowchart of a first method for determining an attached network according to Embodiment 1 of the present invention; FIG. 3 is a simplified flowchart of a second method for determining an attached network according to Embodiment 1 of the present invention; The method for determining an attached network provided in the second embodiment is simplified by a flowchart; FIG. 5 is a simplified flowchart of the method according to the second embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a mobile terminal according to Embodiment 3 of the present invention; FIG.

6b is a schematic structural diagram of a network list generating unit in a mobile terminal according to Embodiment 3 of the present invention;

6c-6e are three schematic structural diagrams of a network selection unit in a mobile terminal according to Embodiment 3 of the present invention. detailed description

In order to further clarify the technical solutions of the embodiments of the present invention, the technical solutions provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Embodiment 1

The network selection method is provided by the mobile node MN (Mobile Node) in the communication network between two different access technologies (such as WiMAX and 3GPP).

As shown in Figure 1, the specific steps of this embodiment are as follows:

Step 101: The MIH User (Media Independent Handover User) unit of the MN sends an MIH information acquisition request message, for example, MIH_Get_Information Request, to the MIHF (Media Independent Handover Function) unit. .

Step 102: The MIHF unit sends the MIH_Get_Information Request message to the Media Independent Information Server (MIIS), and the message carries an indication for acquiring network information around the MN.

Step 103: The MIIS extracts information about the surrounding network (the 3GPP network and the WiMAX network in the surrounding network in this embodiment) according to the information indication carried in the MIH_Get_Information Request message, and encapsulates the extracted information. The MIHF information acquisition response message, such as MIH_Get_Information Response, is sent to the MIHF unit of the MN. The information about the surrounding network includes: data rate, QoS capability, security mechanism, service cost or service capability provided by the network, where the service capabilities include: IMS (Internet Protocol Multimedia Subsystem), CAMEL (Customized Applications for Mobile network) Enhanced Logic, customized applications for mobile network enhanced logic), FAX (fax) or emergency calls.

Step 104: The MIHF unit forwards the MIH_Get_Information Response message to the MIH User unit.

Step 105: The MIH User unit is configured according to preset policy information (including the policy set by the MN itself). The information about the information or the operator's policy) and the acquired surrounding network (3GPP network and WiMAX network) information generate a list of networks sorted according to priority. The priority of the 3GPP network in this embodiment is higher than the priority of the WiMAX network. Of course, the order of priorities is different according to the actual conditions and preset policies of different networks.

Step 106: The MIH User unit sends an MIH scan request message, such as an MIH Scan Request, to the MIHF unit, and instructs it to scan the 3GPP network and the WiMAX network in the network list.

Step 107a and step 107b, the MIHF unit respectively sends a link layer scan request message, such as MIH Scan Request, to the network access points PoA-Cl and PoA-C2 of the 3GPP network and the WiMAX network for network scanning.

Step 108: After scanning the 3GPP network and the WiMAX network, the MIHF unit sends an MIH scan response message carrying the scan result, for example, MIH—Scan Response, to the MIH User unit, where the scan result includes signal quality information of the 3GPP network and the WiMAX network.

Step 109: The MIH User unit learns the signal quality information of each network according to the scan response message, identifies the network whose signal quality meets the requirements, and selects the network according to the priority selection network in the network whose signal quality meets the requirements according to the preset policy information. . For example, the signal quality of the 3GPP network and the WiMAX network in this embodiment both meet the requirements, and then the MN will select to attach to the 3GPP network with high priority in the network list. Similarly, if there are three networks in the network list sorted according to the following priorities: 3GPP network, WiMAX network and WiFi network, and the MN recognizes that the signal quality of the WiMAX network and the WiFi network meets the requirements, then the MN will be in the WiMAX network and the WiFi network. A high priority WiMAX network is selected for attachment.

Step 110: The MIH User unit sends an attach request message, such as an Attach Request, to the network access point PoA-Cl of the 3GPP network.

Step 111a - Step 111b, the MN performs authentication and registration to the 3GPP network server (Authorization Authentication Charging Server AAA/Home Subscriber Server HSS).

Step 112: If the authentication and registration in steps 11la-llb are successful, the PoA-Cl of the 3GPP network returns an attach response message to the MIH User unit of the MN, for example, Attach Response, MN attachment. 3GPP network.

As shown in FIG. 2, the process of determining the attached network in the foregoing embodiment is: first determining the priority of each scanned network, then scanning each network to obtain the signal quality of each network, and finally selecting the network to attach, the specific process is as follows:

Step 201: The MN acquires information about the surrounding network from the Media Independent Information Server (MIIS).

Step 202: The MN generates a prioritized network list according to the preset policy information and the acquired surrounding network information.

Step 203: The MN scans each network in the network list to obtain signal quality information of all networks in the network list.

Step 204: In the network where the signal quality meets the requirements, the MN selects the network according to the priority of the network list for attachment.

As shown in FIG. 3, the embodiment further provides a second process for determining an attached network, that is, scanning each network in the network list first, and then prioritizing the networks whose signal quality meets the requirements, and finally selecting the network for attachment. The specific process is as follows:

Step 301: The MN acquires information about the surrounding network (the WiMAX network and the 3GPP network) from the MIIS.

Step 302: The MN generates a network list according to the preset policy information and the acquired surrounding network information. Step 303: The MN scans each network in the network list to obtain signal quality information of all networks in the network list.

Step 304: According to the known signal quality information of all networks, identify the network whose signal quality meets the requirements, and prioritize the network whose signal quality meets the requirements according to the preset policy and the network information, and select the network for attachment according to the priority.

According to the second process of determining the attached network, step 105 can be replaced with:

Step 1051: The MIH User unit obtains information about the surrounding network (3GPP network and WiMAX network) according to preset policy information (policy information set by the MN itself or policy information of the operator). Generate a list of networks.

Replace step 109 with:

Step 1091: The MIH User unit learns the signal quality information of each network according to the scan response message, identifies the network whose signal quality meets the requirements, and prioritizes the network whose signal quality meets the requirements according to the preset policy information and the information of each network. Sort, select the highest priority network to attach. For example, in this embodiment, the MIH User unit knows the signal quality of the 3GPP network and the WiMAX network. The MN will select the 3GPP network for attachment.

With the network selection method provided in this embodiment, the mobile terminal can select an appropriate network to connect between networks of multiple access technology types. Embodiment 2

The network selection method provided by the embodiment of the present invention is specifically described by taking the network selection between the communication networks of the two different access technologies (such as WiMAX and 3GPP) as an example. The technical solution provided by this embodiment differs from the technical solution provided in the first embodiment in that the MN performs scanning and network selection in priority order after obtaining the prioritized network list. As shown in FIG. 4, the method of this embodiment is as follows:

Step 401: The MN obtains information about the surrounding network from the MIIS.

Step 402: The MN generates a prioritized network list according to the preset policy information and the acquired surrounding network information.

Step 403: The MN scans the network with the highest priority in the network list, and obtains the signal quality information of the network.

Step 404: If the signal quality of the network with the highest priority meets the requirements, go to step 406. If the signal quality of the network with the highest priority does not meet the requirements, go to step 405.

Step 405: Scan the next priority network, and perform step 404.

In step 406, the MN performs network attachment. As shown in FIG. 5, the specific implementation steps of this embodiment are as follows:

Step 501 - Step 505 is the same as step 101 - step 105, and details are not described herein again.

Step 506: The MIH User sends an MIH_Scan Request message to the MIHF, and instructs it to scan the 3GPP network with the highest priority in the network list.

Step 507: The MIHF sends a link layer MIH Scan Request message to the 3GPP network for scanning.

Step 508: The MIHF scans the 3GPP network, and sends an MIH_Scan Response message carrying the scan result to the MIH User unit, where the scan result includes the signal quality information of the 3GPP network.

Step 509: The MIH User unit learns the signal quality information of the 3GPP network according to the scan response message. If the signal quality of the 3GPP network meets the requirements, step 510 is performed. If the signal quality of the 3GPP network does not meet the requirement, the priority of the scan network list is low. The network of the 3GPP network (in this embodiment, the WiMAX network may be a network in actual use), and the signal quality of the scanned network meets the requirements, step 510 is performed.

Step 510: The MIH User unit sends an Attach Request message to the PoA-Cl of the 3GPP network.

Steps 511a-511b, the MN performs authentication and registration to the 3GPP network server (AAA/HSS).

Step 512, if the authentication and registration in steps 511a-511b are successful, the PoA-Cl of the 3GPP network returns an Attach Response to the MIH User unit of the MN, and the MN attaches to the 3GPP network.

With the network selection method provided in this embodiment, the mobile terminal can select an appropriate network to connect between networks of multiple access technology types.

Step 101 and step 501 in the foregoing two embodiments may be implemented in the case that the MN initially enters the network for network selection, or in the case that the MN has already camped on an initial network, after a period of time, the MN is in the In the idle state, the MN is to be implemented in a scenario of network reselection, that is, the network selection method provided by the embodiment of the present invention is applicable to the network selection field at the time of initial network access. Scene, also applies to scenes of network reselection.

The foregoing two embodiments are all examples of network selection or network reselection between MNs of two access technology types, but the application of the present invention is not limited to the case of the above two embodiments, and may also be used for MN in two. Network selection or network reselection between networks of the above access technology types.

Embodiment 3

This embodiment describes in detail a mobile terminal, which can perform network selection of an initial network access or network reselection in an idle state between networks of multiple access technology types. As shown in FIG. 6a, the mobile terminal 600 includes: a network information acquiring unit 601, a network list generating unit 602, a scanning unit 603, and a network selecting unit 604, where

The network information obtaining unit 601 acquires information of the surrounding network, the network list generating unit 602 generates a network list according to the information of the surrounding network, and the scanning unit 603 scans the network in the network list to obtain signal quality information of the scanned network, and the network selecting unit 604 Selecting a network in the network list for attachment according to the network list and signal quality information of the scanned network. The surrounding networks are networks of different access technology types.

As shown in FIG. 6b, the network list generating unit 602 may further include: a sorting unit 6021 and a network list generating subunit 6022, where

The sorting unit 6021 prioritizes the surrounding networks according to the preset policy information and the information of the surrounding network, and the network list generating sub-unit 6022 generates the network list sorted according to the priority according to the prioritization of the sorting unit 6021.

As shown in Figures 6c-6e, the network selection unit 604 can have the following structures:

The network selection unit 604 as shown in FIG. 6c further includes an identification unit 6041 and a network selection sub-unit 6042. In the mobile terminal 600 of such a structure, the scanning unit 603 scans each of the networks in the prioritized network list to obtain signal quality information of all networks, and the identification unit 6041 identifies the signal quality information of all networks. The network having the signal quality meeting the requirements, the network selection sub-unit 6042, in the network in which the signal quality identified by the identification unit 6041 meets the requirements, is selected according to the priority selection network. The network selection unit 604 as shown in FIG. 6d further includes: an identification unit 6043 and an instruction unit 6044. In the mobile terminal 600 of this structure, the scanning unit 603 scans the network in the network list in order of priority, and transmits the signal quality information of the currently scanned network to the identification unit 6043 in the network selection unit 604, and the identification unit 6043 is based on The signal quality information of the currently scanned network identifies the signal quality of the currently scanned network, and sends the identification result to the command unit 6044. When the recognition result is that the signal quality of the currently scanned network satisfies the requirement, the command unit 6044 instructs the mobile terminal. The current scanned network is selected for attachment. When the recognition result is that the signal quality of the currently scanned network does not meet the requirement, the instruction unit 6044 instructs the scanning unit 603 to scan the network of the next priority.

The network selection unit 604 as shown in Fig. 6e further includes: an identification unit 6045, a sorting unit 6046, and a network selection subunit 6047. The identifying unit 6045 identifies the network whose signal quality meets the requirements according to the signal quality information of the scanned network, and the sorting unit 6046 prioritizes the network whose signal quality meets the requirements according to the preset policy information and the information of the surrounding network, and the network selector Unit 6047 selects the network for attachment based on the prioritization of ranking unit 6046.

The information of the surrounding network in this embodiment includes: a data rate, a quality of service capability, a security mechanism, a service cost, or a service capability provided by the network.

With the mobile terminal provided in this embodiment, it is possible to select an appropriate network to connect between networks of multiple access technology types.

Embodiment 4

The embodiment provides a communication system for implementing the network selection method in the first embodiment and the second embodiment. The communication system includes: a mobile terminal and a media independent information server, where the mobile terminal can be applied to the mobile terminal provided in the third embodiment. The media-independent information server stores and provides information to the mobile terminal on the surrounding network, which includes networks of different access technology types.

The information about the surrounding network in this embodiment includes: an access technology type, an access network identifier, a priority level, and the like, and may also include a data rate, a quality of service capability, a security mechanism, and a service provided by the network. Cost or business capability, carrier frequency, etc.

In all of the above embodiments, the process of scanning 3GPP and WiMAX networks includes the process of cell search and cell measurement.

Through the network selection method, the mobile terminal, and the communication system provided by the foregoing embodiments, the mobile terminal can select an appropriate network to connect between networks of multiple access technology types.

A person skilled in the art can understand that all or part of the steps of implementing the above embodiments can be completed by a program to instruct related hardware, and the program can be stored in a computer readable storage medium, such as ROM/RAM, magnetic. Disc or CD.

The foregoing is only a specific embodiment of the embodiments of the present invention, but the scope of protection of the embodiments of the present invention is not limited thereto, and any changes made by those skilled in the art within the technical scope disclosed by the present invention may be Alternatives are intended to be covered by the scope of the present invention. Therefore, the scope of protection of the embodiments of the present invention should be determined by the scope of the claims.

Claims

Claim

A network selection method, the method comprising:

Obtaining information about a surrounding network, where the surrounding network is a network of different access technology types; generating a network list according to the information of the surrounding network;

Scanning the network in the network list to obtain signal quality information of the scanned network;

And selecting a network to attach in the network list according to the network list and signal quality information of the scanned network.

2. The network selection method according to claim 1, wherein the network list is a prioritized network list generated according to preset policy information and information of the surrounding network.

The network selection method according to claim 2, wherein the scanning the network in the network list to obtain the signal quality information of the scanned network is specifically: scanning the network list in priority order Network, get the signal quality information of the currently scanned network.

The network selection method according to claim 3, wherein the selecting the network to perform attachment in the network list according to the network list and the signal quality information of the scanned network includes:

If the signal quality of the currently scanned network meets the requirements, then the currently scanned network is selected for attachment;

If the signal quality of the currently scanned network does not meet the requirements, then the next priority network is instructed to scan until the signal quality of the scanned network meets the requirements, and the scanned network is selected for attachment.

The network selection method according to claim 2, wherein the scanning the network in the network list to obtain the signal quality information of the scanned network is: scanning each network in the network list, obtaining Signal quality information of all networks in the network list.

The network selection method according to claim 5, wherein the selecting the network to perform attachment in the network list according to the network list and the signal quality information of the scanned network includes: Identifying, according to signal quality information of all networks in the network list, a network whose signal quality meets requirements;

In the network where the signal quality meets the requirements, the network is selected for attachment according to the priority of the network list.

The network selection method according to claim 1, wherein the scanning the network in the network list to obtain the signal quality information of the scanned network is: scanning each network in the network list to obtain Signal quality information of all networks in the network list.

The network selection method according to claim 7, wherein the selecting the network to perform attachment in the network list according to the network list and the signal quality information of the scanned network includes:

Identifying a network whose signal quality meets requirements based on signal quality information of all networks in the network list;

The network whose signal quality meets the requirements is prioritized according to preset policy information and information of the surrounding network;

Select the network to attach according to the priority.

The network selection method according to any one of claims 1-8, wherein the process of scanning a network in the network list comprises a process of cell search and cell measurement.

The network selection method according to any one of claims 1-8, wherein the information of the surrounding network comprises: an access technology type, an access network identifier, and a priority level.

The network selection method according to any one of claims 1-8, wherein the signal quality information comprises signal strength information.

12. A mobile terminal, the mobile terminal comprising:

a network information acquiring unit, configured to acquire information about a surrounding network, where the surrounding network is a network of different access technology types;

a network list generating unit, configured to generate a network list according to the information of the surrounding network; a scanning unit, configured to scan a network in the network list, to obtain a signal quality of the scanned network Information

And a network selection unit, configured to select, according to the network list and signal quality information of the scanned network, a network in the network list to perform attaching.

The mobile terminal according to claim 12, wherein the network list generating unit comprises:

The first sorting unit is configured to prioritize the surrounding networks according to the preset policy information and the information of the surrounding network.

14. The mobile terminal of claim 13, wherein

The scanning unit is further configured to: scan each network in the network list to obtain signal quality information of all networks in the network list;

The network selection unit further includes:

a first identifying unit, configured to identify, according to signal quality information of all networks in the network list, a network whose signal quality meets requirements;

The first network selection sub-unit is configured to select, according to the priority selection network, the network to be attached in the network whose signal quality recognized by the first identification unit meets the requirement.

15. The mobile terminal of claim 13, wherein

The scanning unit is further configured to: scan the network in the network list according to a priority order, and obtain signal quality information of the currently scanned network;

The network selection unit further includes:

a second identifying unit, configured to identify, according to signal quality information of the currently scanned network, a signal quality of the currently scanned network, to obtain a recognition result;

An instruction unit, configured to: when the recognition result is that a signal quality of the currently scanned network meets a requirement, instruct the mobile terminal to select the currently scanned network to perform attaching, when the recognition result is a signal quality of a currently scanned network When the requirement is not met, the scanning unit is instructed to scan the next priority network.

16. The mobile terminal of claim 12, wherein The network selection unit further includes:

a third identifying unit, configured to identify, according to signal quality information of the scanned network, a network whose signal quality meets requirements;

a second sorting unit, configured to prioritize the network whose signal quality meets requirements according to preset policy information and information of the surrounding network;

And a second network selection subunit, configured to select a network for attaching according to a priority order of the second sorting unit.

The mobile terminal according to any one of claims 12-16, wherein the information of the surrounding network comprises: a data rate, a quality of service capability, a security mechanism, a service cost or a service capability provided by the network.

18. A communication system, wherein the communication system comprises:

a mobile terminal, configured to acquire information about a surrounding network, generate a network list according to the information of the surrounding network, scan a network in the network list, obtain signal quality information of the scanned network, according to the network list and the Scanning signal quality information of the network, and selecting a network to attach in the network list;

a media independent information server, configured to store and provide information about the surrounding network;

The surrounding networks are networks of different access technology types.

The communication system according to claim 18, wherein the information of the surrounding network comprises: a data rate, a quality of service capability, a security mechanism, a service cost, or a service capability provided by the network.