KR101233258B1 - System and method for implementation inter-radio access technology handover - Google Patents

Abstract

The present invention discloses a heterogeneous intersystem handover implementation system and method thereof. That is, the first pilot channel (P-CPICH) and the second pilot channel (Secondary-Common Pilot Channel, S-CPICH) including corresponding base station information and each having a predetermined level are located in the asynchronous network. A base station periodically providing the mobile terminal; And receiving the first and second pilot channels from the base station, measuring the power of the received first pilot channel and the second pilot channel, and comparing the measured power with a predetermined system threshold. Thus, according to the comparison result, the mobile terminal for converting from the asynchronous mode to the synchronous mode; including, by preventing unnecessary handover occurring in the overlay (Overlay) area, it is possible to increase the efficiency of the network.

Primary Common Pilot Channel (P-CPICH), Secondary Common Pilot Channel (S-CPICH)

Description

System and method for implementing handover between heterogeneous systems {SYSTEM AND METHOD FOR IMPLEMENTATION INTER-RADIO ACCESS TECHNOLOGY HANDOVER}

The following drawings, which are attached in this specification, illustrate preferred embodiments of the present invention, and together with the detailed description of the present invention, serve to further understand the technical spirit of the present invention. It should not be construed as limited to.

1 is a schematic configuration diagram of a system for implementing a handover between heterogeneous systems according to an embodiment of the present invention.

2 is a schematic configuration diagram of a mobile terminal according to an embodiment of the present invention.

3 is a view for explaining a handover condition according to an embodiment of the present invention.

4 and 5 are flowcharts illustrating a method for handover between heterogeneous systems according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100: base station 200: mobile terminal

210: RF transceiver 220: WCDMA modem

230: CDMA modem 240: control unit

250: storage

The present invention relates to a heterogeneous inter-system handover method, and more particularly, to implement an inter-heterogeneous inter-system handover that prevents unnecessary handover operation in an asynchronous network by additionally applying a common pilot channel transmitted from a base station of an asynchronous network. A system and method thereof are provided.

The third generation of mobile communication systems, also called International Mobile Technology (IMT-2000), uses Code Division Multiple Access (CDMA) technology, which provides packet-based text and digitization wherever mobile users are in the world. It provides a consistent service for transmitting voice, video and multimedia data at high speeds of 2Mbps or more. The third generation mobile communication system is classified into asynchronous WCDMA (Wide CDMA), which is adopted as the European standard, and synchronous CDMA-2000, which is adopted as the American standard.

WCDMA is based on the Global System for Mobile Communication (GSM) and General Packet Radio Services (GPRS), which are widely used in Europe and elsewhere, and is also called a Universal Mobile Telecommunication Service (UMTS) system. CDMA-2000 is based on second-generation CDMA systems such as IS-95 and J-STD008 used in Korea, the United States, and Japan. Currently, the two systems are harmonized, and accordingly, various techniques for compatibility between the two systems have been studied. An important one of them is a technique related to handover that can occur when a mobile terminal moves between two systems.

Handover is a technology that allows a user to communicate without interruption of a call when the mobile terminal moves from one cell to another cell of the mobile communication system. There are two methods of handover. One is a soft handover that communicates using a plurality of channels in an overlapping area of two or more cells, and then disconnects the corresponding channel when one channel quality falls below a reference value. It is a hard handover that attempts to disconnect the channel of the previous cell and attempt to connect to an adjacent cell when moving.

In this regard, when the multimode multi-band (MM-MB) terminal capable of communicating with both the asynchronous network (WCDMA) and the synchronous network (CDMA) moves from the asynchronous network to the synchronous network, Handover occurs. This is because the mobile terminal cannot connect channels simultaneously with two different mobile communication networks. The mobile terminal in communication measures and reports information on neighboring cells to the base station when the received pilot signal is less than the reference value or requested by the base station. As described above, the operation of measuring information on neighboring cells is called cell searching. The reported measurement information is used as determination information on handover generated when the mobile terminal moves to another cell during communication.

In this regard, the mobile station is a synchronization network when the strength of the primary common pilot channel (P-CPICH) transmitted from the base station of the asynchronous network in the boundary region between the asynchronous network and the synchronous network is less than the reference value Perform handover operation to switch to.

However, the above-described conventional implementation of handover may occur in an overlay area that provides an asynchronous mobile communication system in a communication environment in which a synchronous network is established, in addition to the normal handover operation in the boundary area. have. That is, in the overlay area, the output power of the primary common pilot channel transmitted from the base station is attenuated due to in-building and noise and the like, causing the mobile terminal to receive an unnecessary handover operation. There was a problem of decreasing efficiency.

The present invention was created to solve the problems inherent in the prior art as described above, and an object of the present invention is to further apply a common pilot channel (CPICH) transmitted from a base station of an asynchronous network (WCDMA). By providing a handover method between heterogeneous systems to prevent unnecessary handover operation of a mobile terminal in an asynchronous network.

In accordance with an aspect of the present invention, a system for implementing a handover between heterogeneous systems is provided. The system includes a first pilot channel (Primary) including corresponding base station information and each having a predetermined level. A base station periodically providing a common pilot channel (P-CPICH) and a second pilot channel (S-CPICH) to a mobile terminal located in an asynchronous network; And receiving the first and second pilot channels from the base station, measuring the power of the received first pilot channel and the second pilot channel, and comparing the measured power with a predetermined system threshold. The mobile terminal converts the asynchronous mode into the synchronous mode according to the comparison result.

In the configuration, the base station, the heterogeneous inter-system handover implementation system, characterized in that for providing the first pilot channel and the second pilot channel output power spaced apart from each other by a predetermined level.

In the above configuration, the first pilot channel has an output value larger than the second pilot channel by the predetermined level.

In the above configuration, the mobile terminal measures Received Signaling Code Power (RSCP) of the first pilot channel and the second pilot channel, such that the measured power of the first pilot channel is less than the threshold value, and simultaneously the second The mode is switched only when the predetermined value is larger than the RSCP of the pilot channel.

In the configuration, the mobile terminal measures the energy / noise ratio (Ec / No) based on the measured power of the first pilot channel and the second pilot channel, so that the energy / noise ratio of the first pilot channel is less than the threshold value At the same time, the mode is changed only when the value is larger than the energy / noise ratio of the second pilot channel by a predetermined level.

In the configuration, the mobile terminal measures a signal loss based on the measured powers of the first pilot channel and the second pilot channel, so that the signal loss of the first pilot channel and the second pilot channel is determined by the mobile terminal. If it is larger than the threshold value, the mode is converted.

In the above configuration, the asynchronous mode is a wide code division multiple access (WCDMA) mode.

In the above configuration, the synchronization mode is a code division multiple access (CDMA) mode.

According to another aspect of the present invention, there is provided a multimode multiband (MM-MB) terminal operating in an asynchronous mode: the terminal transmits an asynchronous signal received from a base station to a protocol defined in an asynchronous network. Thus, asynchronous modem for call processing; Receiving a first pilot channel (P-CPICH) and a second pilot channel (Secondary-Common Pilot Channel, S-CPICH) each having a predetermined level from the base station to measure the power, the measured power A control unit for converting from the asynchronous mode to the synchronous mode according to a comparison result with a preset system threshold; A program storage unit for storing the threshold value; And a synchronous modem for the synchronous mode operation.

In the configuration, the control unit measures RSCP (Received Signaling Code Power) of the first pilot channel and the second pilot channel, so that the measured power of the first pilot channel is less than the threshold, and at the same time the second pilot The mode is switched only when the value is larger than the measured power of the channel.

In the configuration, the control unit measures the energy / noise ratio (Ec / No) based on the measured power of the first pilot channel and the second pilot channel, the energy / noise ratio of the first pilot channel is less than the threshold value At the same time, the mode is changed only when the value is larger than the energy / noise ratio of the second pilot channel.

In the above configuration, the control unit measures a signal loss based on the measured power of the first pilot channel and the second pilot channel, so that the signal loss of the first pilot channel and the second pilot channel is the threshold. If greater than the value, the mode is switched.

In the above configuration, the control unit turns off the synchronous modem while the asynchronous modem is in operation and turns off the asynchronous modem while the synchronous modem is in operation.

In the above configuration, the asynchronous mode is a wide code division multiple access (WCDMA) mode.

In the above configuration, the synchronization mode is a code division multiple access (CDMA) mode.

According to yet another aspect of the present invention, a method for implementing heterogeneous inter-system handover is provided, which comprises: a) a primary pilot channel (P-CPICH) and a first pilot channel, each base station having a predetermined level; Transmitting a second pilot channel (Secondary-Common Pilot Channel, S-CPICH) on an asynchronous network (WCDMA); b) acquiring a scrambling code by receiving the first and second pilot channels by a mobile terminal located on the asynchronous network to recognize the base station; c) measuring, by the mobile terminal, Received Signaling Code Power (RSCP) of the first and second pilot channels; And d) if the measured power of the first and second pilot channels is less than a predetermined system threshold (Own System Threshold), the mobile terminal converts from an asynchronous mode to a synchronous mode (CDMA).

In the above configuration, in the step a), the base station specifies and outputs the output power of the first pilot channel to a value greater than the output power of the second pilot channel by a predetermined level.

In the above configuration, step d) comprises: d-1) determining whether the measured power of the first pilot channel is less than the threshold value; d-2) comparing the measured power of the first pilot channel with the measured power of the second pilot channel if the measured power of the first pilot channel is less than the threshold; d-3) if the measured power of the first pilot channel is greater than the measured power of the second pilot channel by a predetermined level, converting from the asynchronous mode to the synchronous mode.

In the above configuration, step d-3) converts from the asynchronous mode to the synchronous mode only when the measured power of the first pilot channel is greater than the measured power of the second pilot channel by a level width designated by the base station.

(Example)

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic block diagram of a heterogeneous inter-system handover implementation system according to an embodiment of the present invention.

As shown in FIG. 1, the system basically provides an overlay for providing an asynchronous mobile communication service (WCDMA) in a communication environment in which a synchronous network (CDMA) is established. A base station 100 for transmitting an asynchronous signal to the area A; And a mobile terminal 200 located in the overlay area to receive an asynchronous mobile communication service from the base station. Here, reference numeral 'B' in the drawing denotes a synchronous network, reference numeral 'C' in the figure denotes a boundary region where the asynchronous network and the synchronous network intersect, and in the boundary region C, the normality of the mobile terminal 200 is normal. Handover, that is, the conversion from the asynchronous mode to the synchronous mode is made.

The base station 100 includes a primary pilot channel (P-CPICH) and a second pilot channel (Secondary-Common Pilot Channel, S-CPICH) each having a predetermined level. It is provided periodically to the mobile terminal 200 located on the Wide Code Division Multiple Access. Here, the first and the second pilot channel includes a base station identification code, and is transmitted in a forward direction from the base station 100 to the mobile terminal 200 to the mobile terminal 200 in a frame of 10ms. Meanwhile. The output power of the first pilot channel is set to have a value larger than the second pilot channel by a predetermined level and is output from the base station 100.

The mobile terminal 200 receives the first and second pilot channels from the base station, recognizes the base station 100 that is provided with an asynchronous service through acquiring a scrambling code, and receives the received first pilot. Received Signaling Code Power (RSCP) of the channel and the second pilot channel is measured so that the asynchronous mode to the synchronous mode (CDMA, Code Division Multiple Access) only when the measured power (dBm) is less than the threshold specified by the system. Convert. For reference, the mobile terminal 200 measures energy / noise ratio (Ec / No) and transmission loss based on the measured power, in addition to the RSCP, according to a system setting, and a threshold corresponding to each. By comparing with, the same operation can be performed. Here, the threshold value is a set value in consideration of the attenuation ratios of the first and second pilot channels measured in the boundary region C in which normal handover is performed.

To this end, the mobile terminal 200, as shown in Figure 2, the RF transceiver 210 for transmitting and receiving and demodulating the RF signal; A WCDMA modem 220 for processing the asynchronous signal received through the RF transceiver 210 according to a protocol defined in an asynchronous network; A CDMA modem 230 for processing a synchronization signal received through the RF transceiver 210 according to a protocol defined in a synchronization network; Receiving the first pilot channel and the second pilot channel provided from the base station 100 to measure power (dBm), and if the measured power is less than the system specified threshold (Own System Threshold), the mobile terminal 200 Control unit 240 for converting a) from the asynchronous mode to the synchronous mode; And a program storage unit 250 storing a threshold value.

Referring to FIG. 3, the controller 240 measures the received power of the first pilot channel and the second pilot channel, so that the measured power of the first pilot channel is less than the threshold value and simultaneously the second pilot. The operation mode of the mobile terminal 200 is converted from the asynchronous mode to the synchronous mode only when the value is larger than the measured power of the channel. Meanwhile, the controller 240 turns off the CDMA modem 230 while the WCDMA modem 220 is operating, and turns off the WCDMA modem 240 while the CDMA modem 230 is operating. Switch.

Hereinafter, a heterogeneous inter-system handover method according to an embodiment of the present invention will be described with reference to FIGS. 4 and 5. 4 and 5 are flowcharts illustrating a method for handover between heterogeneous systems according to an embodiment of the present invention.

First, the base station 100 assigns a first pilot channel (P-CPICH) and a second pilot channel (Secondary-Common Pilot Channel, S-CPICH) each having a predetermined level to the overlay area A. FIG. Send it (S110). At this time, the base station 100 outputs the output power of the first pilot channel to a value larger than the output power of the second pilot channel by a predetermined level.

Thereafter, the mobile terminal 200 located in the overlay area A receives the first and second pilot channels, acquires a scrambling code, and recognizes the base station (S120).

Then, the mobile terminal 220 measures the received signaling code power (RSCP) of the first and second pilot channels (S130), and the measured power of the first and second pilot channels specified by the system (Own) If less than System Threshold), it converts from the asynchronous mode to the synchronous mode (S130). Preferably, as shown in FIG. 5, the mobile terminal 200 determines whether the measured power of the first pilot channel is less than the threshold value (S131), and as a result of the determination, the measured power of the first pilot channel. If is less than the threshold value, the measured power of the first pilot channel is compared with the measured power of the second pilot channel (132). Subsequently, if the measured power of the first pilot channel is greater than the measured power of the second pilot channel by a predetermined level, the mobile terminal 200 converts from the asynchronous mode to the synchronous mode (S133). That is, the mobile terminal 200 converts from the asynchronous mode to the synchronous mode only when the measured power of the first pilot channel is greater than the measured power of the second pilot channel by the level width designated by the base station.

As can be seen above, the heterogeneous inter-system handover implementation system and method according to the present invention, in addition to the primary common pilot channel (P-CPICH) transmitted from the base station, the secondary common pilot channel (Secondary) -Common Pilot Channel (S-CPICH) is additionally transmitted and included in the reference item of the mode conversion of the mobile terminal, thereby preventing unnecessary handover occurring in the overlay area, thereby increasing network efficiency. .

Although the present invention has been described in detail with reference to the preferred embodiments, the present invention is not limited to the above-described embodiments, and the present invention belongs to the present invention without departing from the gist of the present invention as claimed in the following claims. Anyone skilled in the art will have the technical idea of the present invention to the extent that various modifications or changes are possible.

Claims (19)

A mobile terminal including corresponding base station information and having a first pilot channel (P-CPICH) and a second pilot channel (Secondary-Common Pilot Channel, S-CPICH) each having a predetermined level in an asynchronous network. Providing a base station periodically; And Receiving the first and second pilot channels from the base station, measuring the power of the received first and second pilot channels, and comparing the measured power with a predetermined system (Own System Threshold) And a mobile terminal for converting from the asynchronous mode to the synchronous mode according to the comparison result. The mobile terminal includes: Received Signaling Code Power (RSCP) of the first pilot channel and the second pilot channel is measured so that the measured power of the first pilot channel is less than the threshold and at the same time greater than the measured power of the second pilot channel. Change the mode only if it is a value, or The energy / noise ratio (Ec / No) is measured based on the measured power of the first pilot channel and the second pilot channel, so that the energy / noise ratio of the first pilot channel is less than the threshold, and at the same time The heterogeneous inter-system handover implementation system, wherein the mode is changed only when the value is larger than the energy / noise ratio. The method of claim 1, wherein the base station, And providing the first pilot channel and the second pilot channel with output power spaced apart from each other by the mobile terminal to the mobile terminal. The method of claim 2, wherein the first pilot channel, And an output value greater than the second pilot channel by the predetermined level. delete delete The mobile terminal of claim 1 or 2, wherein the mobile terminal comprises: The signal loss is measured based on the measured powers of the first pilot channel and the second pilot channel. When the signal loss of the first pilot channel and the second pilot channel is greater than the threshold value, the mode is changed. Handover implementation system, characterized in that for converting. The method of claim 1, wherein the asynchronous mode, A system for implementing handover between heterogeneous systems, characterized in that it is in Wide Code Division Multiple Access (WCDMA) mode. The method of claim 1, wherein the synchronization mode, A system for implementing handover between heterogeneous systems, characterized in that it is a code division multiple access (CDMA) mode. In a multimode multiband (MM-MB) terminal operating in an asynchronous mode, An asynchronous modem for processing the asynchronous signal received from the base station according to a protocol defined in the asynchronous network; Receiving a first pilot channel (P-CPICH) and a second pilot channel (Secondary-Common Pilot Channel, S-CPICH) each having a predetermined level from the base station to measure the power, the measured power A control unit for converting from the asynchronous mode to the synchronous mode according to a comparison result with a preset system threshold; A program storage unit for storing the threshold value; And Includes; a synchronous modem for the synchronous mode operation, The control unit, Received Signaling Code Power (RSCP) of the first pilot channel and the second pilot channel is measured so that the measured power of the first pilot channel is less than the threshold and at the same time greater than the measured power of the second pilot channel. Change the mode only if it is a value, or The energy / noise ratio (Ec / No) is measured based on the measured powers of the first pilot channel and the second pilot channel, so that the energy / noise ratio of the first pilot channel is less than the threshold and at the same time Multi-mode multi-band terminal, characterized in that for changing the mode only when the value greater than the energy / noise ratio. delete delete The method of claim 9, wherein the control unit, The signal loss is measured based on the measured powers of the first pilot channel and the second pilot channel. When the signal loss of the first pilot channel and the second pilot channel is greater than the threshold value, the mode is changed. Multi-mode multi-band terminal, characterized in that for converting. The method of claim 9, wherein the control unit, And turn off the synchronous modem while the asynchronous modem is in operation, and turn off the asynchronous modem while the synchronous modem is in operation. The method of claim 9, wherein the asynchronous mode, A multi-mode multi-band terminal, characterized in that it is in Wide Code Division Multiple Access (WCDMA) mode. The method of claim 9, wherein the synchronization mode, A multi-mode multi-band terminal, characterized in that it is in Code Division Multiple Access (CDMA) mode. a) A base station uses a first pilot channel (P-CPICH) and a second pilot channel (Secondary-Common Pilot Channel, S-CPICH) each having a predetermined level, and asynchronous network (WCDMA) Access on (Access); b) acquiring a scrambling code by receiving the first and second pilot channels by a mobile terminal located on the asynchronous network to recognize the base station; c) measuring, by the mobile terminal device, the power of the first and second pilot channels; d) converting from the asynchronous mode to the synchronous mode (CDMA, Code Division Multiple Access) when the mobile terminal is less than the measured power of the first and second pilot channels and a predetermined system threshold (Own System Threshold); , Step d), d-1) determining whether the measured power of the first pilot channel is less than the threshold value; d-2) comparing the measured power of the first pilot channel with the measured power of the second pilot channel if the measured power of the first pilot channel is less than the threshold; d-3) converting from the asynchronous mode to the synchronous mode only when the measured power of the first pilot channel is a predetermined level larger than the measured power of the second pilot channel. How to implement intersystem handover. The method of claim 16, wherein step a) The base station designates and outputs the output power of the first pilot channel to a value greater than the output power of the second pilot channel by a predetermined level. delete The method of claim 16, wherein d-3), And converting from the asynchronous mode to the synchronous mode only when the measured power of the first pilot channel is greater than the measured power of the second pilot channel by a level width specified by the base station.

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