JP2016039554A - Mobile communication terminal and capability information reporting method for mobile communication terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce capability information of a mobile communication terminal that should be reported to a network, without adding a novel interface.SOLUTION: In the mobile communication terminal that is adaptable to a plurality of frequency bands, it is discriminated whether at least either first frequency related information included in common priority information reported from the network by notice information or second frequency related information included in individual priority information reported from the network by an individual signal is acquired as frequency related information of an in-zone cell. In the case where at least either the first frequency related information or the second frequency related information is acquired, a frequency capability that should be reported is determined on the basis of at least either the first frequency related information or the second frequency related information, and the determined frequency capability is reported to a radio control apparatus as the capability information of the mobile communication terminal.SELECTED DRAWING: Figure 2

Description

  The present invention relates to the field of mobile communications, and in particular, to mobile technology notification technology.

  In the Third Generation Partnership Project (3GPP), a W-CDMA (Wideband-Code Division Multiple Access) mobile communication system based on Code Division Multiple Access (CDMA) technology has been specified. It is popular in many countries including Europe. The W-CDMA system is also called “3G” or “UMTS (Universal Mobile Telecommunications System)”.

  Long Term Evolution (LTE), which evolved 3G, defines specifications for higher speed, larger capacity, and lower delay than 3G communication systems, and Orthogonal Frequency Division Multiplexing (OFDM) The method is adopted.

  Each of these wireless communication systems is called RAT (Radio Access Technology). In addition to the W-CDMA and LTE wireless communication systems described above, RAT also includes wireless communication systems such as the cdma2000 and GSM / EDGE systems. Various RATs are operated by various operators at various frequencies in various countries and regions, and in some cases, a plurality of RATs can be used in the same region.

  As a method of switching connection destinations between different RATs, there is a method called Inter-RAT handover. The handover is characterized in that the RAT can be switched while maintaining the connection with the network including the radio, and packet loss does not occur. Unlike redirection, handover can suppress occurrence of packet retransmission processing due to wireless disconnection. On the other hand, in order to implement various communication controls such as handover at the switching destination RAT, it is necessary to acquire mobile equipment (User Equipment: UE) capability at the switching destination RAT. In the case of Inter-RAT handover, various information needs to be exchanged between RATs via the core network, such as acquiring information in advance and notifying the switching destination RAT during handover.

  In LTE, the number of frequency bands that can be handled by mobile communication terminals increases, and it is necessary to notify mobile functional capabilities for each combination of frequency bands, as typified by carrier aggregation. Information is growing. When control information to be notified over the air including capability information of the mobile communication terminal is enlarged, a problem of communication quality degradation occurs such as communication connection being delayed in the old system. For example, when performing a handover from W-CDMA (3G) to LTE, when a communication capability at the handover destination (LTE) is acquired from a mobile communication terminal in a W-CDMA system, the communication speed is inferior to LTE. Problems such as communication connection delay occur in the W-CDMA system.

  In order to deal with this problem, efforts are being made to limit the amount of control signal to be notified over the air. As one of them, a method has been proposed in which a new interface is added, the necessary capability information is instructed from the network to the mobile communication terminal, and only the necessary capability information is acquired from the mobile communication terminal (for example, (See Patent Document 3).

3GPP TS25.331 ver. 12.1.0 3GPP TS36.331 ver. 12.1.0 3GPP TSG-RAN WG2 # 86, R2-142435

  In a new network such as LTE, it is possible to limit the amount of capability information exchanged over the air by adding a new interface. However, in a network where system development is not active like the W-CDMA system, it is difficult to add a new interface, and there is a possibility that the same solution as LTE may not be adopted.

  Therefore, it is an object to provide a technique capable of reducing the amount of capability information of a mobile communication terminal to be notified to a network without adding a new interface.

  In order to solve the above-mentioned problem, when the mobile communication terminal acquires the frequency related information of the serving cell and the neighboring cell from the network by broadcast information or individual signals, the mobile communication terminal notifies the network based on the frequency related information. The frequency capability that needs to be determined is determined and notified to the network as capability information of the mobile communication terminal. Thereby, the amount of capability information to be notified is reduced.

More specifically, in one aspect of the present invention, a mobile communication terminal capable of supporting a plurality of frequency bands is provided. This mobile communication terminal
As frequency related information of the serving cell, first frequency related information included in the common priority information notified from the network by broadcast information and second priority information included in the individual priority information notified from the network by an individual signal. A determination unit for determining whether or not at least one of the frequency related information is acquired;
When at least one of the first frequency related information and the second frequency related information is acquired, it is necessary to notify based on the at least one of the first frequency related information and the second frequency related information A notification processing unit for determining a certain frequency capability, and notifying the determined frequency capability to the radio network controller as capability information of the mobile communication terminal;
Have

  Without adding a new interface, the amount of capability information of the mobile communication terminal to be notified to the network can be reduced.

It is a figure which shows the structural example of the mobile communication system of embodiment. It is a flowchart which shows the mobile functional capability notification process in a mobile communication terminal. It is a figure which shows the example of an expansion | deployment in the case of notifying common priority information or individual priority information as a mobile functional capability. It is a figure which shows the example of expansion | deployment in the case of notifying default frequency band information as a mobile functional capability. It is a schematic block diagram of the mobile communication terminal and radio | wireless control apparatus of embodiment.

  FIG. 1 is a diagram illustrating a configuration example of a mobile communication system 1 to which the present invention is applied. The LTE wireless access system and the 3G (W-CDMA) wireless access system are providing services in geographically identical or overlapping areas. A radio network controller (RNC) 20 is connected to the 3G core network 21. The RNC has jurisdiction over one or more cells 22-1 and 22-2 (collectively referred to as “cell 22” where appropriate), and the mobile communication terminal 10 is located in a cell in which the RNC 20 communicates with a base station (not shown). Wireless communication.

  An LTE base station apparatus (evolved Node B: eNB) 30 is connected to the LTE core network 31. The eNB 30 has jurisdiction over one or more cells 32-1 and 32-2 (collectively referred to as “cell 32” where appropriate), and the mobile communication terminal 10 performs radio communication with the eNB 30 in the cell in which it is located. The mobile communication terminal 10 can communicate with both the LTE and 3G radio access schemes, and in the area where the LTE cell 32 and the 3G cell 22 overlap, the mobile communication terminal 10 has a high priority according to the radio conditions, frequency conditions, etc. Wait for the cell and connect. In the example of FIG. 1, different RATs such as LTE and 3G are taken as an example, but communication with another RAT such as GSM (registered trademark) (Global System for Mobile communications) is possible in addition to LTE and 3G. There may be.

  In a geographical area where the 3G cell 22 and the LTE cell 32 overlap, when the mobile communication terminal 10 is handed over from LTE to 3G, the eNB 30 needs to know the 3G capability of the mobile communication terminal 10. Also, when the mobile communication terminal 10 performs inter-RAT PS-HO (Inter-RAT packet switched handover) or SRVCC (Single Radio Voice Call Continuity) from LTE to 3G, If the 3G side does not know the capability of the mobile communication terminal 10, the mobile communication terminal 10 cannot be returned to LTE. The capability of the mobile communication terminal 10 includes whether or not handover between RATs is possible, whether or not LTE radio quality measurement can be performed during 3G communication, in which frequency band of LTE communication is possible, etc. Contains information.

  In the embodiment, the mobile communication terminal 10 autonomously narrows down the capability information to be notified to the network without receiving designation of necessary information from the network, and notifies the network of the reduced amount of capability information. For example, when communication is started in a 3G cell by handover from the LTE cell 32 to the 3G cell 22, the capability information to be notified by the own station is determined even if the necessary information is not specified from the RNC 20. Notify RNC 20.

  FIG. 2 is a flowchart of the capability information notification method in the mobile communication terminal 10. It is assumed that the mobile communication terminal 10 is located in the 3G cell 22. The mobile communication terminal 10 notifies the communication capability information of the local station to the network at the start of communication in the 3G cell 22.

  The mobile communication terminal 10 determines whether or not the frequency information included in the common standby priority information (hereinafter also referred to as “common priority information”) “Common Priority” is acquired from information broadcast in the serving cell. (S11). The information to be broadcast is, for example, 3G system information called “SIB19”, and is notified to all mobile communication terminals located in the cell. The common priority information includes information indicating the frequency and priority of another RAT that overlaps the same area, and is information for moving the mobile communication terminal 10 to a higher priority frequency. In the case of the example in FIG. 1, “Common Priority” includes information indicating frequencies usable in the 3G cell 22, frequencies usable in the LTE cell 33, and priorities of the 3G cell 22 and the LTE cell 33. Including.

  Whether the mobile communication terminal 10 has acquired the frequency information with “Common Priority” (Yes in S11) or not (No in S11), the mobile communication terminal 10 next uses the frequency with the individual priority information “Dedicated Priority”. It is determined whether information is acquired (S12 and S15). “Dedicated Priority” is frequency information individually notified to the mobile communication terminal 10. “Dedicated Priority” individually notifies the standby frequency of the mobile communication terminal 10 or the operating frequency of the network, and is notified as a part of mobility information, for example.

  When the mobile communication terminal 10 has acquired frequency information with “Common Priority” and has acquired frequency information with “Dedicated Priority” (Yes in S12), it is notified with “Common Priority” and “Dedicated Priority”. Information related to the frequency is notified to the RNC 20 (S13).

  When the mobile communication terminal 10 has not acquired frequency information with “Common Priority” (No in S11), but has acquired frequency information with “Dedicated Priority” (Yes in S15), the mobile communication terminal 10 “ Only the information related to the frequency notified by “Dedicated Priority” is notified to the RNC 20 (S16).

  If the mobile communication terminal 10 has not acquired frequency information regardless of whether it is “Common Priority” or “Dedicated Priority” (No in S15), it is determined whether it has default frequency band information (S17). The default frequency band information may be only information on the frequency band provided by each provider, or may include information on each channel in the band. As default frequency band information, frequency information corresponding to each business operator may be held as a list, or a list of default frequency information that is normally operated may be held.

  When the mobile communication terminal 10 has default frequency band information (Yes in S17), only the default frequency band information is notified to the RNC 20 as capability information (S18). When the mobile communication terminal 10 does not have default frequency band information (No in S17), all capability information is notified to the RNC 20 (S19). The capability information in this case includes all frequency bands that can be communicated by the mobile communication terminal 10 and the maximum transmission / reception bandwidth, reception sensitivity, carrier aggregation capability, and information on component carriers that can be handled.

  In this way, the mobile communication terminal 10 autonomously limits the capability information to be notified to the network among the information held by itself, and reduces the amount of capability information notified wirelessly.

  FIG. 3 shows a development example in the case where the mobile communication terminal 10 has both “Common Priority” frequency-related information and “Dedicated Priority” frequency-related information. When the mobile communication terminal 10 has both “Common Priority” frequency-related information and “Dedicated Priority” frequency-related information (Yes in S12 of FIG. 2), the mobile communication terminal 10 is “Common Priority”. It is determined whether or not the total amount of the frequency-related information acquired and the frequency-related information acquired by “Dedicated Priority” exceeds a predetermined threshold (S21). When the total information amount is within the threshold (No in S21), the frequency-related information acquired by “Common Priority” and the frequency-related information acquired by “Dedicated Priority” are all notified to the RNC 20.

  When the total amount of the frequency related information acquired by “Common Priority” and the frequency related information acquired by “Dedicated Priority” exceeds a predetermined threshold (Yes in S21), only one of the frequency related information is sent to the RNC 20 Notification is made (S23). Which frequency-related information is to be notified is determined based on the past communication history of the mobile communication terminal 10, position information, the contents of frequency-related information acquired by “Common Priority” and “Dedicated Priority”, and the like.

  For example, in the situation where the priority of the LTE cell 32 is set high in the “Common Priority” included in the broadcast information, and the standby frequency or the operating frequency in the 3G cell 22 is individually notified in the “Dedicated Priority”, It is assumed that the frequency of voice calls (3G) by CS (Circuit Switched) fallback or the like is higher than the frequency of data communication in the latest history of the mobile communication terminal 10. In this case, the mobile communication terminal 10 determines that the frequency of presence in 3G is high, and determines the frequency capability that needs to be notified based on the frequency related information acquired by “Dedicated Priority” in which the priority of 3G is set high. , Notify the RNC 20. In the same situation, when the mobile communication terminal 10 frequently performs packet data communication (LTE), it is determined that the presence frequency in LTE is high, and the LTE priority is set high. The frequency capability that needs to be notified is determined from the frequency-related information acquired in step (B), and the RNC 20 is notified. The frequency capability that needs to be notified may be determined based on the frequency of transition to the frequency listed in each of “Common priority” and “Dedicated Priority”.

  FIG. 4 shows a development example when the mobile communication terminal 10 notifies only the default frequency band information. When the mobile communication terminal 10 holds neither the frequency-related information of “Common Priority” nor the frequency-related information of “Dedicated Priority” and notifies only the default frequency band division as capability information (Yes in S17 in FIG. 2) The mobile communication terminal 10 determines whether or not the amount of default frequency band information exceeds a predetermined threshold (S31). This threshold value may be the same value as or different from the threshold value used in S21 of FIG. If the amount of the default frequency band information is within the threshold (No in S31), the mobile communication terminal 10 notifies the RNC 20 of all the held default frequency band information as capability information (S32).

  When the amount of default frequency band information to be held exceeds the threshold (Yes in S31), the mobile communication terminal 10 notifies only a part of the default frequency band information to the RNC 20 (S33). Which part of the default frequency band information to hold is determined from the past communication history, position information, etc. of the mobile communication terminal 10. For example, a communication network of a specific operator is established in a certain geographical area, and the mobile communication terminal 10 is set in a predetermined state based on a history of a communication cell and a frequency with which the mobile communication terminal 10 waits in the communication network of the operator or performs communication. The frequency information and the frequency band information operated by the operator are notified to the RNC 20. Further, the frequency capability that needs to be notified may be determined based on the location history of a specific communication base station such as a 3G femto BTS (Base Transceiver Station) or the icon display history of the waiting RAT.

  As shown in FIGS. 3 and 4, by further narrowing down the frequency related information to be notified by the mobile communication terminal 10, the amount of control information transmitted and received wirelessly can be suppressed without adding a new interface.

  FIG. 5 is a schematic configuration diagram of the mobile communication terminal 10 and the RNC 20. The RNC 20 includes a system information notification unit 24, an individual information notification unit 23, and a capability information reception unit 25. The system information notification unit 24 notifies the mobile communication terminal located in the 3G cell 32 of system information such as “SIB19” as broadcast information. The individual information notification unit 23 individually notifies the mobile communication terminal 10 of cell priority and frequency information used in overlapping cells. The capability information receiving unit 25 receives a limited amount of capability information from the mobile communication terminal 10 via a base station (not shown).

  The mobile communication terminal 10 includes a system information acquisition unit 11, an individual information acquisition unit 13, a Common Priority (common priority information) storage unit 12, a Dedicated Priority (individual priority information) storage unit 14, and a default frequency storage unit. 15, a capability notification information determination unit 16, and a capability information notification processing unit 17.

  The system information acquisition unit 11 acquires system information such as SIB19 notified from the network. The individual information acquisition unit 13 acquires individual information notified individually from the network. The common priority storage unit 12 stores common priority information included in the system information. The Dedicated Priority storage unit 14 stores individual priority information included in the individual information. The default frequency storage unit 15 stores the default frequency band information when the default frequency band information is set in the mobile communication terminal 10.

  The capability notification information determination unit 16 determines capability notification information to be notified to the network based on the common priority information, the individual priority information, and the default frequency band information at the start of communication or the like. Specifically, the capability information to be notified to the network is limitedly selected and determined according to the processing flow of FIGS. Based on at least the presence / absence of frequency-related information acquired by “Common Priority”, the presence / absence of frequency-related information acquired by “Dedicated Priority”, and the presence / absence of default frequency band information, the capability information to be notified to the network is narrowed down to a certain range. . The capability information notification processing unit 17 notifies the RNC 20 of the capability notification information determined by the capability notification information determination unit 16 via the base station.

  The common priority information and the individual priority information stored in the Common Priority storage unit 12 and the Dedicated Priority storage unit 14 may be deleted after completion of handover to a different RAT or when communication is disconnected.

  In the above-described example, “Common Priority” and “Dedicated Priority” included in the SIB 19 of the 3G wireless access method are taken as an example, but equivalent frequency information broadcast in a system such as LTE or GSM (registered trademark) is used. It may be used as a basis for capability information. For example, frequency-related information may be acquired from common priority information included in other types of SIBs transmitted from the LTE network. Similarly, information related to frequency may be acquired from the individual priority information included in the LTE “RRC Connection” message.

  In the example described above, narrowing down of capability information to be notified to the network has been described by taking an inter-RAT handover as an example. However, capability information to be notified when the communication capability is notified to the network within the same RAT. Narrowing may be applied. For example, when notifying the communication capability to the eNB 30 in the LTE network, the capability information to be notified may be narrowed down based on the priority information and default frequency information held by the mobile communication terminal 10. In this case, the radio control function of the eNB 30 is a radio control apparatus that receives notification of capability information from the mobile communication terminal 10. In addition to the priority information and the default frequency information, the carrier aggregation support information of the mobile communication terminal 10 may be used as a basis for narrowing down the capability information to be notified.

  According to the method and configuration of the embodiment, it is possible to narrow down the capability information to be notified by the autonomous determination of the mobile communication terminal 10 without the designation or instruction of the necessary capability information from the network. Thereby, the amount of capability information of the mobile communication terminal transmitted / received in the uplink can be reduced, and the influence of communication connection delay and the like can be avoided.

DESCRIPTION OF SYMBOLS 1 Mobile communication system 10 Mobile communication terminal 11 System information acquisition part (broadcast information acquisition part)
12 Common Priority (Common Priority Information) Storage Unit 13 Individual Information Acquisition Unit 14 Dedicated Priority (Individual Priority Information) Storage Unit 15 Default Frequency Band Information Storage Unit 16 Capability Notification Information Determination Unit 17 Capability Information Notification Processing Unit 20 RNC (Radio) Control device)
21 3G core network 22, 22-1, 22-2 3G cell 23 Individual information notification unit 24 System information notification unit 25 UE capability information reception unit 30 eNB (radio control device)
31 LTE core network 32, 32-1, 32-2 LTE cell

Claims (7)

A mobile communication terminal capable of supporting a plurality of frequency bands,
As frequency related information of the serving cell, first frequency related information included in the common priority information notified from the network by broadcast information and second priority information included in the individual priority information notified from the network by an individual signal. A determination unit for determining whether or not at least one of the frequency related information is acquired;
When at least one of the first frequency related information and the second frequency related information is acquired, it is necessary to notify based on the at least one of the first frequency related information and the second frequency related information A notification processing unit for determining a certain frequency capability, and notifying the determined frequency capability to the radio network controller as capability information of the mobile communication terminal;
A mobile communication terminal characterized by comprising: The determination unit, when both the first frequency related information and the second frequency related information are acquired, communication history of the mobile communication terminal, location information, the first frequency related information and the Selecting one of the first frequency related information and the second frequency related information based on at least part of the content of the second frequency related information;
The notification processing unit determines a frequency capability that needs to be notified based on the selected one of the frequency related information, and notifies the radio control device of the determined frequency capability as the capability information.
The mobile communication terminal according to claim 1. An information acquisition unit for acquiring information from the network;
Further comprising
The mobile communication terminal according to claim 2, wherein the information acquisition unit acquires a general priority and a frequency of the serving cell as the first frequency related information. An information acquisition unit for acquiring information from the network;
Further comprising
The mobile communication terminal according to claim 2, wherein the information acquisition unit acquires a priority and a frequency of the serving cell dedicated to the mobile communication terminal as the second frequency related information. The determination unit determines whether default frequency band information is set in the mobile communication terminal when neither the first frequency-related information nor the second frequency-related information is acquired from the network. Judgment
When the default frequency band information is set, the notification processing unit notifies the radio control apparatus of the default frequency band information as the capability information of the mobile communication terminal.
The mobile communication terminal according to claim 1. The determination unit selects the default frequency band information based on at least a part of the content of the communication history, position information, and default frequency band information of the mobile communication terminal,
The notification processing unit notifies the wireless control device of the default frequency band information as the capability information;
The mobile communication terminal according to claim 5. In a mobile communication terminal capable of supporting a plurality of frequency bands, as frequency related information of a serving cell, first frequency related information included in common priority information notified by broadcast information from the network, and an individual signal from the network Determining whether or not at least one of the second frequency related information included in the individual priority information notified by
When at least one of the first frequency related information and the second frequency related information is acquired, it is necessary to notify based on the at least one of the first frequency related information and the second frequency related information Determining a certain frequency capability, and notifying the determined frequency capability to the radio controller as capability information of the mobile communication terminal,
A capability information notification method characterized by the above.

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