KR20090054776A - Apparatus for performing handover between networks and method thereof - Google Patents

Abstract

An apparatus for performing handover between networks and a method thereof are provided to reduce the power consumption of a mobile communication terminal remarkably and the increase of the time for handover and to decrease the probability of failure. A handover request signal generator for a mobile communication network(21) selects one of pilot signals stored at a mobile communication network, and the selected signal is determined as a preliminary handover request signal. A handover request signal generator for a portable internet network(22) selects one of the pilot signals of the portable internet networks. The selected signal is determined as the preliminary handover request signal. A handover request signal generator for a wireless LAN communication network(23) selects one of the pilot signals of the wireless LAN. The selected signal is determined as the preliminary handover request signal.

Description

Manganese handover device and method thereof {APPARATUS FOR PERFORMING HANDOVER BETWEEN NETWORKS AND METHOD THEREOF}

The present invention relates to a manganese handover device and a method thereof.

With the development of communication technology, various wireless communication networks have emerged at the request of users who want to receive multimedia services regardless of wired or wireless communication networks. Current wireless communication networks include mobile communication networks such as CDMA and WCDMA, portable Internet networks, and wireless local area networks (WLANs).

When a mobile communication terminal (not shown) such as a mobile phone moves out of the service area of each wireless communication network or enters a service area of another wireless communication network, from a base station (or access point) of another service area of the same wireless communication network. A service may be received from a base station (or access point) in a service area of a different wireless communication network. The former case is called a handover between homogeneous networks, and the latter case is called a handover between heterogeneous networks.

When performing handover between heterogeneous networks, the mobile communication terminal scans all channels of all wireless communication networks which have the possibility of handover, thereby searching for an optimal communication channel, which requires a lot of searching time.

In addition, since the service area of the WLAN is relatively narrower than that of the mobile communication network, when the user of the mobile communication terminal is moving, the number of handovers is increased because the time out of the service area of the currently communicating WLAN is shorter than that of other wireless communication networks. Lose. As a result, the handover time increases due to the frequent scan time, and the frequent handover operation greatly affects the power consumption of the mobile communication terminal.

In addition, in the case of a wireless LAN, access points may be installed by various operators or individuals, and thus, operation compatibility between operators may not be achieved. Therefore, since operators cannot perform handovers between different wireless LANs or precise handovers, only unnecessary channel scan time is wasted.

Therefore, the technical problem to be achieved by the present invention is to reduce the power consumption due to frequent handover by reducing the probability of collision during handover.

Another technical problem to be achieved by the present invention is to reduce the time required to acquire a new channel in case of a handover failure.

A manganese handover apparatus of a mobile communication terminal according to an aspect of the present invention is a manganese handover apparatus of a mobile communication terminal connected to a first wireless communication network having a first base station and a second wireless communication network having a second base station, The manganese handover device is a storage unit for storing a first pilot signal group transmitted from the first base station of the first wireless communication network and the second pilot signal group transmitted from a second base station of the second wireless communication network, the storage A handover request signal generation unit for a first wireless communication network which selects at least one first pilot signal from among a first pilot signal group stored in the second unit and selects one of the selected first pilot signals as a first preliminary handover request signal Select at least one second pilot signal from among a second pilot signal group stored in the storage unit, and select one of the selected second pilot signals A handover request signal generation unit for a second wireless communication network selecting one as a second preliminary handover request signal, and one preliminary handover request among the first preliminary handover request signal and the second preliminary handover request signal And a handover request signal selector for selecting a signal as a final handover request signal and transmitting the signal as a handover request signal to a wireless communication network which has transmitted the final handover request signal.

The handover request signal generator for the first wireless communication network and the handover request signal generator for the second wireless communication network, as well as signal-to-interference and noise ratio (SINR), as well as data rate, transmission rate, frequency bandwidth, frequency band, and signal The first preliminary handover request signal or the second preliminary handover request signal may be selected in consideration of any one or more delay levels.

The handover request signal generator for the first wireless communication network and the handover request signal generator for the second wireless communication network may each randomly select the at least one first pilot signal and the at least one second pilot signal. .

Preferably, the first wireless communication network and the second wireless communication network are one of a mobile communication network, a portable communication network, and a wireless LAN.

A manganese handover method according to another aspect of the present invention receives a first pilot signal group transmitted from a first base station of a first wireless communication network and a second pilot signal group transmitted from a second base station of a second wireless communication network during a reception interval. And storing at least one first and second pilot signals in each of the first pilot signal group and the second pilot signal group during each calculation period. Selecting one of the selected first pilot signals as a first preliminary handover request signal and selecting one of the selected second pilot signals as a second preliminary handover request signal, wherein the at least one selected for each operation period Selecting one of the first preliminary handover request signals as the first final preliminary handover request signal, Selecting one of the at least one second preliminary handover request signal selected per operation interval as a second final preliminary handover request signal, and the first final preliminary handover request signal and the second final preliminary handover request Requesting handover by selecting one of the signals as a final handover request signal and transmitting it to the first base station or the second base station.

The handover request step may include a handover by transmitting the final handover request signal to a base station that has transmitted the first final preliminary handover request signal or the second final preliminary handover request signal selected as the final handover request signal. It is good to ask.

The handover request step may include determining a communication channel through which the first final preliminary handover request signal or the second final preliminary handover request signal selected as the final handover request signal is allocated, and the allocation of the determined communication channel. The method may further include requesting the base station.

The manganese hand-over method determines whether a handover acknowledgment signal is transmitted from a base station that has transmitted the last handover request signal during a response waiting period, and the handover is not performed during the response waiting period. If it fails, determining whether the random access time exceeds the maximum allowable time, if the random access time exceeds the maximum allowable time, determining the out of coverage area, and the random access time is the maximum allowable time If the time is not exceeded, the method may further include increasing the random access time by increasing the number of operation intervals by "1".

The manganese handover method determines whether the number of handover failures reaches a set number of times when the handover fails because the handover approval signal is not transmitted during the response waiting period, and the number of handover failures is set. Determining that the number of handover failures reaches the predetermined number of times when the number of handover failures reaches the predetermined number of times, and increasing the number of operation intervals by "1" to increase the random access time. It may include.

Preferably, the first wireless communication network and the second wireless communication network are one of a mobile communication network, a portable communication network, and a wireless LAN.

In the selecting of the first and second preliminary handover request signals, the at least one first pilot signal and the second pilot signal may be randomly selected within the first pilot signal group and the second pilot signal group. Do.

The first and second preliminary handover request signals, the first and second final preliminary handover request signals, and the last handover request signals may include not only a signal-to-interference and noise ratio (SINR) but also a data rate, a transmission rate, It may be selected in consideration of any one or more of the frequency bandwidth, the frequency band, the degree of signal delay.

A manganese handover method according to another aspect of the present invention includes a first pilot signal group transmitted from a first base station of a first wireless communication network and a second pilot signal group transmitted from a second base station of a second wireless communication network during a reception interval. Receiving and storing, selecting one pilot signal group from the first pilot signal group and the second pilot signal group, including at least one operation period, and in the selected pilot signal group during each operation period Selecting at least one pilot signal, selecting one of the selected pilot signals as a preliminary handover request signal, and one preliminary handover request signal among at least one preliminary handover request signal selected for each operation period Is selected as the last handover request signal so that By transmitting to the second base station comprises the step of requesting a handover.

The handover request step may request a handover by transmitting the handover request signal to a base station that has transmitted a pilot signal selected as the handover request signal.

The handover request step may further include determining a communication channel through which a pilot signal selected as the handover request signal is transmitted, and requesting the base station to allocate the determined communication channel.

The manganese handover method determines whether a handover acknowledgment signal is transmitted from a base station that has transmitted the handover request signal during a response waiting period, and the handover fails because the handover acknowledgment signal is not transmitted during the response waiting period. If so, determining whether the random access time exceeds the maximum allowable time, if the random access time exceeds the maximum allowable time, determining the out of coverage area, and the random access time is the maximum allowable time If not exceeding, may further include increasing the random access time by increasing the number of operation intervals by "1".

The manganese handover method determines whether the number of handover failures reaches a set number of times when the handover fails because the handover approval signal is not transmitted during the response waiting period, and the number of handover failures is set. Determining that the number of handover failures reaches the predetermined number of times when the number of handover failures reaches the predetermined number of times, and increasing the number of operation intervals by "1" to increase the random access time. can do.

In the preliminary handover request signal selection step, the at least one pilot signal may be randomly selected within the selected pilot signal group.

The first wireless communication network and the second wireless communication network may be one of a mobile communication network, a portable communication network, and a wireless LAN.

The pilot signal group, the preliminary handover request signal, and the final handover request signal include one or more of data rate, transmission rate, frequency bandwidth, frequency band, and signal delay as well as signal-to-interference and noise ratio (SINR). It is preferable to select in consideration.

According to the present invention, the probability of the handover failure is reduced, the time increase for the handover and the power consumption of the mobile communication terminal are greatly reduced.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "electrically connected" with another element in between. .

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. have.

In this specification, a mobile station (MS) is a terminal, a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), a user equipment (User Equipment). It may also refer to a user equipment (UE), an access terminal (AT), and the like, and may include all or some functions of a mobile terminal, a subscriber station, a portable subscriber station, a user device, and the like.

In the present specification, a base station (BS) is an access point (AP), a radio access station (Radio Access Station, RAS), a Node B (Node B), a base transceiver station (Base Transceiver Station, BTS), MMR ( Mobile Multihop Relay) -BS and the like, and may include all or part of functions such as an access point, a radio access station, a Node B, a base transceiver station, and an MMR-BS.

Next, a manganese handover apparatus and a method thereof according to an embodiment of the present invention will be described according to the accompanying operation.

First, a structure of a wireless communication network used in an embodiment of the present invention will be described with reference to FIG. 1.

1 illustrates a structure of a wireless communication network according to an embodiment of the present invention.

As shown in FIG. 1, a wireless communication network according to an exemplary embodiment of the present invention includes a mobile communication network 100, a portable internet network 200, and a wireless LAN 300.

The mobile communication network 100 is a network providing a mobile communication service using a mobile station, which is a mobile communication terminal (not shown) such as a cellular phone, and wirelessly providing data communication using a communication method such as CDMA, WCDMA, or CDMA 1ⅹ. It's a network.

The portable internet network 200 is a wireless communication network that provides ultra-high speed data communication with mobility using a mobile Wimax (also called WiBro) communication scheme.

The mobile communication network 100 and the portable internet network 200 are provided with base stations 101 and 201 to support a service wirelessly.

Wireless LAN 300 is to provide a LAN (LAN) service by providing a wireless access point (AP, AP) in a LAN service environment to support the service wirelessly. In order to service the WLAN 300, an IEEE 802.11, 802.16, or Wi-Fi method is used.

As shown in FIG. 1, one mobile communication network 100 and one portable Internet network 200 each include one base station 101 and 201. As described above, one wireless LAN 300 includes: One access point (AP) 301 serving as a base station is provided. In the present embodiment, the term base station includes not only the base stations 101 and 201 of the mobile communication network 100 and the portable Internet network 200 but also the access point 301 of the wireless LAN 300.

The coverage area by the operations of the base stations 101, 201, and 301 is reduced to the size of the mobile communication network 100, the portable Internet network 200, and the wireless LAN 300, and conversely, each wireless communication network is supported. The size of the bandwidth is reduced in the order of the wireless LAN 300, the portable Internet network 200 and the mobile communication network (100).

In FIG. 1, the base station 101 of the mobile communication network 100 overlaps with the base station 201 of the portable internet network 200.

Then, when handover to another service area is performed by the movement of the mobile communication terminal (not shown), the handover method will be described with reference to FIG.

2 is an operation flowchart of a manganese handover method according to an embodiment of the present invention.

First, when the communication status with the current base station BS1, such as signal strength, transmission rate, delay time, signal processing speed, etc., does not satisfy the setting condition, the mobile communication terminal MS sends a call to the base station BS1. The handover execution is notified (S101).

Next, the mobile communication terminal MS transmits a handover request signal to the corresponding base station BS2 of the wireless communication network selected by the mobile communication terminal MS (S102). The selected wireless communication network may be one of a mobile communication network, a portable internet network, and a wireless LAN. In addition, the mobile communication terminal MS selects and transmits a desired communication channel.

Therefore, when the communication channel selected by the mobile communication terminal MS is available, the base station BS2 transmits a handover approval signal for allowing handover to the mobile communication terminal MS (S103).

Then, the mobile communication terminal MS informs the base station BS1 of the base station BS2 currently selected for handover (S104). For this reason, the current base station BS1 informs the information of the newly selected base station BS2 to the server to which it is connected, so that communication with the new base station BS2 can be made, and the new base station BS2 can communicate with the mobile communication terminal MS. Information about, for example, tells the transmission rate (S105).

Then, the mobile communication terminal MS disconnects the communication with the current base station BS1 and starts communication with the new base station BS2.

However, in step S102, because the communication channel selected by the mobile communication terminal MS is in use by another mobile communication terminal, the newly selected base station BS2 fails to approve the handover request and thus is selected by the base station BS2. The hand is allowed until the set time (timeout time) elapses after the disallowed signal is transmitted to the mobile communication terminal MS or after the mobile communication terminal MS transmits the handover request signal in step S102 (S202). When the over grant signal is not transmitted from the corresponding base station BS2, that is, when the handover fails, the mobile communication terminal MS repeats the operations of steps S202 to S206 to find a new base station. Perform a handover.

However, when the number of times of handover failure reaches the set time, the mobile communication terminal MS indicates that it is a "out of call right area", and communication is disconnected.

Alternatively, according to an alternative embodiment, in step S102, when the newly selected base station BS2 transmits a disapproval signal to the mobile communication terminal MS, the base station BS2 transmits an available communication channel to the mobile communication terminal. It can also be recommended for (MS). In this case, the mobile communication terminal MS may examine whether the newly recommended communication channel is used by the base station BS2 to accept the use of the newly recommended communication channel or re-execute handover to find a new base station.

As described above, in order to perform handover between networks according to the present embodiment, the mobile communication terminal (MS) transmits a handover request signal by selecting a base station of one wireless communication network that is most suitable among several wireless communication networks.

Next, an example of an operation of generating a handover request signal for one wireless communication network to transmit a handover request signal to one wireless communication network among a plurality of wireless communication networks according to an embodiment of the present invention is illustrated in FIGS. The description will be made with reference to 5.

3 is a block diagram of a control unit of a mobile communication terminal according to an embodiment of the present invention.

4 is a diagram illustrating a structure of an example of a communication packet according to an embodiment of the present invention. 5 is a timing diagram illustrating a process of generating a handover request signal according to an embodiment of the present invention, and FIG. 6 is an operation flowchart of an example of a manganese handover method according to an embodiment of the present invention.

In order to generate a handover request signal for one wireless communication network, a mobile communication terminal according to an embodiment of the present invention should be provided with a signal processing device such as a modem having a control unit shown in FIG.

Referring to FIG. 3, a modem of a mobile communication terminal according to an embodiment of the present invention includes a control unit 30 including a communication packet storage unit 10 and a signal processing unit 20 connected to the communication packet storage unit 10. It is provided.

 The communication packet storage unit 10 is a storage device such as a buffer or a memory, and receives and stores communication packets transmitted between the base station and the mobile communication terminal. Unlike FIG. 3, the controller 30 may be designed as a separate component and mounted outside the controller 30.

The communication packet is transmitted at predetermined intervals from the mobile communication network, the portable communication network and the wireless LAN.

As shown in FIG. 4, the structure of each communication packet existing in one frame includes a pilot signal group 41, a downlink map 42, an uplink map 43, and a downlink data area including a plurality of pilot signals. 44, divided into an uplink data area 45.

The pilot signal is transmitted for each communication channel of the mobile communication network, the portable communication network and the wireless LAN.

The downlink map 42 is an area in which information required for downlink communication is performed from a base station to a mobile communication terminal, and includes, for example, an identification number of the base station, a MAC address of the mobile communication terminal, whether a channel is allocated, The allocated communication channel information is included.

The uplink map 43 is an area in which information necessary for uplink communication is written from a mobile communication terminal to a base station. For example, an identification number of the base station, a MAC address of the mobile communication terminal, and a communication channel for communication. Information such as this is included.

The downlink data area 44 is an area to which data transmitted during downlink is written, and the uplink data area 45 is an area to which data transmitted during uplink is written.

In this embodiment, since the communication channels of the mobile communication network and the portable Internet network may be about 32 channels, the pilot signal group may include 32 pilot signals. In addition, since the communication channel of the WLAN may be about 11, the pilot signal group may include 11 pilot signals. The communication packet shown in FIG. 4 represents a pilot signal group having 32 pilot signals.

In this case, since signal synchronization between the mobile communication network, the portable communication network, and the wireless LAN is not performed with each other, the transmission timing of the communication packet may be different for each wireless communication network.

The mobile communication network and the portable Internet network perform handover using a predetermined number of spreading codes having different values, for example, 32 handover spreading codes. Therefore, a communication packet transmitted from a base station of a mobile communication network or a portable internet network is transmitted using a handover spreading code, and a handover including a handover spreading code from a mobile communication terminal to a base station of a mobile communication network or a portable internet network. When the spreading code signal is received, the base station determines the handover spreading code signal as the handover request signal. Similarly, the WLAN uses a predetermined number of frequencies having different bandwidths, for example, 11 handover frequencies for handover. Therefore, the communication packet transmitted from the base station of the wireless LAN is transmitted using the handover frequency. When the handover frequency signal is received from the mobile communication terminal to the base station of the wireless LAN, the base station requests a handover of the handover frequency signal. Judging as a signal.

The frequency band, frequency bandwidth, and frame width used in the communication packets of the mobile communication network, the portable Internet network, and the wireless LAN are different from each other, but the frequency bandwidths of the communication packets transmitted through the same wireless communication network are the same. In addition, the frequency bandwidth of the pilot signals in the same wireless communication network is also the same. For example, a frequency band of a communication packet of a mobile communication network is about 2.1 GHz, a frequency band of a communication packet of a portable internet network is about 2.3 GHz, and a frequency band of a communication packet of a wireless LAN may be about 2.4 GHz. In addition, the frame size may be about 2ms in a mobile communication network, about 5ms in a portable Internet network, and at least about 1ms in a wireless LAN.

3, the signal processing unit 20 includes a handover request signal generator 21 for a mobile communication network, a handover request signal generator 22 for a portable Internet network, and a handover request signal generator 23 for a wireless LAN. And a handover request signal selector 24 connected to these generators 21, 22, 23.

The handover request signal generation unit 21 for the mobile communication network randomly selects one of the pilot signals of the communication packet of the mobile communication network stored in the communication packet storage unit 10 for a given time to reserve the handover request signal. Decide on

The handover request signal generation unit 22 for the portable Internet network reserves a preliminary handover request signal by randomly selecting one of the pilot signals of the communication packet of the portable Internet network stored in the communication packet storage unit 10 for a given signal. Decide on

In addition, the WLAN communication network handover request signal generation unit 23 randomly selects one of the pilot signals of the communication packet of the WLAN stored in the communication packet storage unit 10 for a given time to request a preliminary handover request. Decide on a signal.

At this time, the handover request signal generation unit 21, 22, 23 also displays the information of the communication channel through which each selected preliminary handover request signal is transmitted based on the information of each corresponding communication packet stored in the communication packet storage unit 10. Able to know.

The handover request signal selector 24 selects one of the preliminary handover request signals input from the handover request signal generators 21, 22, and 23 as a final handover request signal, and then transmits a final handover request signal. Transmit as a handover request signal to one base station. At this time, the mobile communication terminal writes the number of the communication channel corresponding to the selected last handover request signal in the uplink map and transmits channel allocation information to be allocated.

Next, an example of an operation of the controller 30 of the mobile communication terminal generating the handover request signal will be described with reference to FIGS. 5 and 6.

First, as shown in FIG. 5A, the maximum allowable time Tmax for selecting one of the pilot signal groups of the communication packets stored in the communication packet storage unit 10 as the final pilot signal is determined by the mobile communication terminal. It is determined in consideration of the moving speed. Of course, the maximum allowable time Tmax is variable according to the change of the moving speed of the mobile communication terminal. Also, the maximum allowable time Tmax is divided into a plurality of time slots, and all time slots have the same time. The time slot time may be longer than at least the largest frame of the communication packet of the mobile communication network, the communication packet of the portable Internet network, and the communication packet of the WLAN.

The time slot also includes at least one receiving slot TL, at least one operation slot TO, and at least one response waiting slot TS.

As shown in FIG. 6, when the operation is started first (S20), the control unit 30 of the mobile communication terminal receives a communication packet received during the reception slot TL (S21) and transmits the communication packet to the communication packet storage unit 10. Save (S22). At this time, the mobile communication terminal, during the reception slot (TL), and stores the first communication packet received among the communication packets transmitted from the base stations of the various mobile communication networks in the vicinity of the communication packet storage unit 10 and The first one of the communication packets transmitted from the base stations of the various portable Internet networks is stored in the communication packet storage unit 10. In addition, the mobile communication terminal, during the reception slot (TL), stores the first communication packet received in the communication packet transmitted from the base stations of several WLANs in the vicinity of the communication packet storage unit 10. As already explained, each communication packet has pilot signal groups CG, WG and LG.

That is, the mobile communication terminal stores in the communication packet storage 10 the communication packets received by the base station of one mobile communication network, the base station of one portable Internet network and the base station of one wireless LAN during the reception slot TL. . However, during the reception slot TL, there may be a wireless communication network that failed to transmit a communication packet. In this case, the communication packet storage unit 10 only stores the communication packets of the received wireless communication network. In the case of Figure 5, during the reception slot (TL), a communication packet is transmitted from all of the base station of one mobile communication network, one portable Internet network, and one wireless LAN, the pilot signal group (CG, One example of WG and LG) is shown in a reception slot (TL) section.

Next, the controller 30 performs a handover request signal generation unit 21 for a mobile communication network, a handover request signal generator 22 for a mobile Internet network, and a wireless LAN hand to perform an operation for generating a handover request signal. Each of the over request signal generators 23 is operated to generate preliminary handover request signals for one operation slot TO.

That is, the handover request signal generator 21 for the mobile communication network randomly selects a pilot signal among a total of 32 pilot signals of the pilot signal group CG during one operation slot TO. At this time, the number of selected pilot signals is also determined randomly. In the case of FIG. 5A, five pilot signals are selected, and communication channels of the selected pilot signals are channels 1, 5, 10, 28, and 29 (CH1, CH5, CH10, CH28, and CH29), respectively. In this embodiment, the reference numeral of the communication channel is also used as the reference numeral of the pilot signal.

Then, one pilot signal having the best transmission state is selected from the selected pilot signals CH1, CH5, CH10, CH28, and CH29, and is designated as a preliminary handover request signal and output to the handover request signal selector 24. In this case, the selection criterion may use a signal-to-interference-and noise ratio (SINR) of each pilot signal.

In the same manner as the operation of the mobile communication network handover request signal generator 21, the portable Internet network handover request signal generator 22 selects a total of four pilot signals CH3, CH5, CH20, and CH23. The dual pilot signal CH20 is designated as a preliminary handover request signal, and the WLAN handover request signal generator 23 also selects a total of two pilot signals CH2 and CH3, and then reserves the pilot signal CH3 as a preliminary handover. The signal is output to the handover request signal selector 24 as a request signal.

Next, the handover request signal selector 24 is the best pilot signal among three preliminary handover request signals CH5, CH20 and CH3 received from each of the generators 21, 22 and 23, for example. For example, the pilot signal CH20 of the portable Internet network is selected and determined as the final handover request signal (S24). The selection criteria at this time may consider not only the signal-to-interference and noise ratio (SINR) of each pilot signal, but also a data rate, a data rate, a frequency bandwidth, a frequency band, and a degree of signal delay.

 Then, the handover request signal selection unit 24 communicates the identification number of the base station, the MAC address of the corresponding mobile communication terminal, the communication channel information for the allocation request, that is, the final handover request signal in the uplink map of the communication packet. Channel (CH20) information and the like is recorded and transmitted to the base station of the portable Internet network, which is the corresponding wireless communication network that has transmitted the final handover request signal CH20, and requests a handover (S25). Accordingly, the handover request signal selector 24 requests allocation of the communication channel CH20 on which the last handover request signal is transmitted as a communication channel for communication with the new base station.

Then, the controller 30 determines whether the handover grant signal arrives from the base station during the response waiting slot TS, that is, determines whether the handover is successful (S26). In FIG. 5A, the pilot signal CH20 shown in the response waiting slot TS section may be a pilot signal selected as the final handover request signal during the operation slot TO for understanding. .

When a handover grant signal is transmitted from the base station during the response waiting slot (TS), that is, a communication packet is transmitted from the base station during the response waiting slot (TS), and the communication channel is allocated to the downlink map of the communication packet. When the handover succeeds due to a hand-over approval signal for approving the communication and the like, the controller 30 stops communication with the existing base station and starts communication with the new base station (S27).

However, when the handover grant signal is not transmitted from the base station during the response waiting slot TS, that is, when the handover fails, the controller 30 determines that the random access time, which is the sum of the total timeslots used, is the maximum allowed time. It is determined whether (Tmax) has been exceeded or the number of handover failures has reached the set number of times (S28).

When the total timeslot time used exceeds the maximum allowable time (Tmax) or the number of handover failures reaches the set number of times, the controller 30 determines that the coverage area is out of range (S29) through the display window of the mobile communication terminal. Indicates that the zone is out of currency, and the call is dropped.

However, if the total sum of the total timeslots used does not exceed the maximum allowable time Tmax and the number of handover failures does not reach the set number of times, the controller 30 adds one more number of arithmetic slots TO. Increasing the random access time by the operation slot (TO) time (S210). Then, the controller 30 proceeds to step S21 and stores the communication packet received during the reception slot TL and including the pilot signal group CG, WG, or LG in the communication packet storage 10.

Subsequent operations are the same as operations S22 to S210 described above except for the handover request signal generation step S23 and the handover request signal selection operation S24.

That is, unlike the handover request signal generation step S23 and the handover request signal selection operation S24 described with reference to FIG. 5A, as shown in FIG. The handover request signal generator 21 randomly selects the pilot signal CH2 during the first operation slot TO1 to select a preliminary handover request signal from the pilot signal group CG received during the reception slot TL. , CH4, CH8, CH11, CH21, CH24, CH30) and then select the best pilot signal CH8 as the first preliminary handover request signal, and during the second operation slot TO2, handover signal randomly After selecting (CH5, CH7, CH28, CH31), the best handover request signal CH5 is selected as the second preliminary handover request signal. The handover request signal generation unit 21 for the mobile communication network again converts the excellent second preliminary handover request signal CH5 among the first and second preliminary handover request signals CH8 and CH5 into the final preliminary handover request signal. Choose.

Similarly to this operation, the handover request signal generation unit 22 and the WLAN handover request signal generation unit 23 for the portable Internet network also have one handover signal CH28 and each of the two operation slots TO1 and TO2. After selecting CH30, CH8, and CH9 as the first and second preliminary handover request signals, each of the first and second preliminary handover request signals CH28 and CH30, CH8 and CH9 are again the last preliminary handover. Select request signals CH28 and CH9.

Then, the handover request signal selector 24 selects the best spare handover request signal among the three final spare handover request signals CH5, CH28, and CH9. For example, the handover signal transmitted through the ninth communication channel from the base station of the WLAN is selected as the final handover request signal.

As described above, each time the handover fails, the number of operation slots TO is increased by one within the allowable range, thereby increasing the number of preliminary handover request signals for each wireless communication network.

As a result of generating a handover request signal for handover between networks, the probability of handover failure is greatly reduced.

That is, since the handover pilot signal is randomly selected within the allowable number, the probability of selecting the same signal as the handover pilot signal randomly selected by another mobile communication terminal is greatly reduced, and the collision probability is greatly reduced.

Furthermore, since the number of arithmetic slots (TO) is increased by one each time the handover fails, the final handover request signal is selected by a random selection operation, and thus the probability of collision is greatly reduced whenever the number of handover failures increases. The probability of over failure is reduced, which in turn reduces the number of handover attempts. As a result, an increase in time for handover and power consumption of the mobile communication terminal are greatly reduced.

In addition, since a pilot signal is randomly selected within a pilot signal group of a mobile communication network, a portable Internet network, or a wireless LAN, the selected pilot signal is used to perform handover with the most suitable communication network. There is no need to scan the communication channels of the network one by one. This saves a lot of time.

Unlike FIG. 5, when the pilot signal group is not transmitted from the at least one wireless communication network among the mobile communication network, the portable Internet network, and the wireless LAN to the control unit 30 of the mobile communication terminal during the reception slot TL, the control unit 30 The final handover request signal is generated using only the pilot signal group of the wireless communication network received during the reception slot TL. In this case, the controller 30 may drive only the handover request signal generation unit related to the pilot signal group of the wireless communication network received during the reception slot TL.

Next, another example of the operation of the controller 30 of the mobile communication terminal generating the handover request signal will be described with reference to FIG. 7.

7 is a flowchart illustrating another example of the manganese handover method according to an embodiment of the present invention.

As shown in FIG. 7, the control unit 30 according to the present example stores the received communication packet in the communication packet storage unit 10 (S31 and S32), and then generates a preliminary handover request signal shown in FIG. 6. Instead of executing (S32), an optimal wireless communication network is selected (S33).

That is, the controller 30 selects a communication packet received from the base station of one wireless communication network which is the best among the communication packets transmitted from the base station of each wireless communication network. In this case, as described above, the signal-to-interference and noise ratio (SINR), transmission rate, transmission rate, frequency bandwidth, frequency band, and signal delay degree of each pilot signal may be considered. For example, one of the communication packets received from the base station of the mobile communication network, the communication packet received from the base station of the mobile Internet network, and the communication packet received from the base station of the wireless LAN is selected.

Then, the controller 30 enables only the handover request signal generator related to the communication packet selected from the handover request signal generators 21, 22, and 23 so that normal operation can be achieved, and the remaining handover request is performed. Disables the state of the signal generator to make it inoperative. For example, when the selected communication packet relates to a portable internet network, the controller 30 operates only the handover request signal generator 22 for the portable internet network and operates the remaining handover request signal generators 21 and 23. Set to inoperative state.

Then, the handover request signal generation unit 22 for the portable Internet network generates one handover request signal through the same operation described with reference to FIG. 6 (S35), and then the base station of the corresponding wireless network, eg For example, the handover request signal is transmitted to the base station of the portable Internet network (S35).

Since the remaining operations S36-S39 and S310 of the control unit 30 except for the above operation are the same as those described with reference to the steps S26-S29 and S210 of FIG. 6, detailed description thereof will be omitted.

According to this exemplary embodiment of the present invention, as in the example described with reference to FIGS. 5 and 6, the probability of handover failure is reduced, the time for handover and power consumption of the mobile communication terminal are greatly reduced. In addition, according to the present example, instead of operating all three handover request signal generators 21, 22, and 23, only one handover request signal generator is driven, so that power consumption of the mobile communication terminal is further increased. Decreases.

Although the present invention is known based on heterogeneous handover, the present invention is not limited thereto, and the technical features of the present invention can be applied to homogeneous handover. In this case, the controller of the mobile communication terminal may include only a storage unit for storing communication packets of a related wireless communication network and one handover request signal generator for generating a handover request signal using the stored communication packets.

The embodiments of the present invention described above are not implemented only through the apparatus and the method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. Implementation may be easily implemented by those skilled in the art from the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 illustrates a structure of a wireless communication network according to an embodiment of the present invention.

2 is an operation flowchart of a manganese handover method according to an embodiment of the present invention.

3 is a block diagram of a control unit of a mobile communication terminal according to an embodiment of the present invention.

4 is a diagram illustrating a structure of an example of a communication packet according to an embodiment of the present invention.

5 is a timing diagram illustrating a process of generating a handover request signal according to an embodiment of the present invention.

6 is a flowchart illustrating an example of a manganese handover method according to an embodiment of the present invention.

7 is a flowchart illustrating another example of the manganese handover method according to an embodiment of the present invention.

Claims (20)

In an inter-network handover apparatus of a mobile communication terminal connecting to a first wireless communication network having a first base station and a second wireless communication network having a second base station, A storage unit for storing a first pilot signal group transmitted from the first base station of the first wireless communication network and a second pilot signal group transmitted from a second base station of the second wireless communication network; A handover request signal for a first wireless communication network which selects at least one first pilot signal from a first pilot signal group stored in the storage unit and selects one of the selected first pilot signals as a first preliminary handover request signal. Generating Part, A handover request signal for a second wireless communication network which selects at least one second pilot signal from a second pilot signal group stored in the storage unit and selects one of the selected second pilot signals as a second preliminary handover request signal. Generating unit, and One preliminary handover request signal is selected from the first preliminary handover request signal and the second preliminary handover request signal as a final handover request signal, and a handover request signal is transmitted to the wireless communication network which transmits the final handover request signal. Handover request signal selection unit Manganese handover device comprising a. In claim 1, The handover request signal generator for the first wireless communication network and the handover request signal generator for the second wireless communication network, as well as signal-to-interference and noise ratio (SINR), as well as data rate, transmission rate, frequency bandwidth, frequency band, and signal The manganese handover apparatus selecting the first preliminary handover request signal or the second preliminary handover request signal in consideration of one or more delay levels. The method of claim 1 or 2, The handover request signal generator for the first wireless communication network and the handover request signal generator for the second wireless communication network respectively randomly select the at least one first pilot signal and the at least one second pilot signal. Device. In claim 1, And the first wireless communication network and the second wireless communication network are one of a mobile communication network, a portable communication network, and a wireless LAN. Receiving and storing a first pilot signal group transmitted from a first base station of a first wireless communication network and a second pilot signal group transmitted from a second base station of a second wireless communication network during a reception interval; And at least one first pilot signal and a second pilot signal in the first pilot signal group and the second pilot signal group, respectively, during each operation period, and selecting the selected first pilot signal. Selecting one as a first preliminary handover request signal, and selecting one of the selected second pilot signals as a second preliminary handover request signal, Selecting one of the at least one first preliminary handover request signal selected for each operation section as a first final preliminary handover request signal, and among the at least one second preliminary handover request signal selected for each operation section Selecting one as the second final preliminary handover request signal, and Requesting handover by selecting one of the first final preliminary handover request signal and the second final preliminary handover request signal as a final handover request signal and transmitting the same to the first base station or the second base station; Manganese handover method comprising a. In claim 5, The handover request step may include a handover by transmitting the final handover request signal to a base station that has transmitted the first final preliminary handover request signal or the second final preliminary handover request signal selected as the final handover request signal. Requesting manganese handover method. In claim 6, The handover request step includes determining a communication channel through which the first final preliminary handover request signal or the second final preliminary handover request signal selected as the final handover request signal is transmitted; and Requesting the base station to allocate the determined communication channel Manganese handover method further comprising The method according to any one of claims 5 to 7, Determining whether a handover acknowledgment signal is transmitted from the base station which transmitted the last handover request signal during the response waiting period; Determining whether a random access time exceeds a maximum allowable time when the handover fails because the handover approval signal is not transmitted during the response waiting period; If the random access time exceeds the maximum allowable time, determining that the coverage area is out of range, and If the random access time does not exceed the maximum allowable time, increasing the number of operation intervals by "1" to increase the random access time; Manganese handover method further comprising. In claim 8, Determining whether the number of handover failures reaches a set number of times when the handover fails because the handover acknowledgment signal is not transmitted during the response waiting period; If the number of handover failures reaches a set number of times, determining that the handover failure area is out of a call right area, and When the number of handover failures reaches the set number of times, increasing the number of operation intervals by "1" to increase the random access time; Manganese handover method further comprising. In claim 5, The first wireless communication network and the second wireless communication network is one of a mobile communication network, a portable communication network and a wireless LAN network handover method. In claim 5, The selecting of the first and second preliminary handover request signals may randomly select the at least one first pilot signal and the at least one second pilot signal within the first pilot signal group and the second pilot signal group. Manganese handover method. In claim 5, The first and second preliminary handover request signals, the first and second final preliminary handover request signals, and the last handover request signals may include not only a signal-to-interference and noise ratio (SINR) but also a data rate, a transmission rate, A network handover method selected by considering at least one of frequency bandwidth, frequency band, and signal delay. Receiving and storing a first pilot signal group transmitted from a first base station of a first wireless communication network and a second pilot signal group transmitted from a second base station of a second wireless communication network during a reception interval; Selecting one pilot signal group from the first pilot signal group and the second pilot signal group, Selecting at least one pilot signal within the selected pilot signal group during each operation period, selecting one of the selected pilot signals as a preliminary handover request signal, and Requesting a handover by selecting one preliminary handover request signal among at least one preliminary handover request signal selected for each operation period as a final handover request signal and transmitting it to the first base station or the second base station; Manganese handover method comprising a. In claim 13, The handover request step is a manganese handover method for requesting a handover by transmitting the handover request signal to the base station that transmitted the pilot signal selected as the handover request signal. In claim 13, The handover request step may include determining a communication channel through which a pilot signal selected as the handover request signal is transmitted, and Requesting the base station to allocate the determined communication channel Manganese handover method further comprising The method according to any one of claims 13 to 15, Determining whether a handover acknowledgment signal is transmitted from the base station which has transmitted the handover request signal during the response waiting period; Determining whether a random access time exceeds a maximum allowable time when the handover fails because the handover approval signal is not transmitted during the response waiting period; If the random access time exceeds the maximum allowable time, determining that the coverage area is out of range, and If the random access time does not exceed the maximum allowable time, increasing the number of operation intervals by "1" to increase the random access time; Manganese handover method further comprising. The method of claim 16, Determining whether the number of handover failures reaches a set number of times when the handover fails because the handover approval signal is not transmitted during the response waiting period; When the number of handover failures reaches a set number of times, determining that the handover failure time is an area of a coverage area; When the number of handover failures reaches the set number of times, increasing the number of operation intervals by "1" to increase the random access time; Manganese handover method further comprising. The method of claim 13, wherein the selecting of the preliminary handover request signal randomly selects the at least one pilot signal within the selected pilot signal group. In claim 13, The first wireless communication network and the second wireless communication network is one of a mobile communication network, a portable communication network and a wireless LAN network handover method. In claim 13, The pilot signal group, the preliminary handover request signal, and the final handover request signal include one or more of data rate, transmission rate, frequency bandwidth, frequency band, and signal delay as well as signal-to-interference and noise ratio (SINR). The manganese handover method chosen by considering.

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