KR20040059686A - Method for selecting the data call service system for mobile phone with dual mode - Google Patents

Abstract

PURPOSE: A method for selecting a data call service system in a dual mode terminal is provided to offer a good effective bandwidth to each data service user by enabling a dual mode wireless terminal, capable of supporting both a CDMA2000 1x system and an EVDO system, to select one of them in case that the two systems are installed in an identical area and try to use a data service of the wireless terminal. CONSTITUTION: If a wireless terminal user's call setup request starts(100), the wireless terminal judges which system is available as a data service system(101). In case that only a CDMA2000 1x system is available, the wireless terminal selects the CDMA2000 1x system(106). If only an EVDO system is available, the wireless terminal the EVDO system(107). In case that both systems are available, the wireless terminal compares the strength of a pilot signal(PS1x) received from the CDMA2000 1x system with the strength of a pilot signal(PSEVDO) received from the EVDO system(102). If the strength of PS1x is larger than the strength of PSEVDO, the wireless terminal compares the strength of PS1x with the sum of the strength of PSEVDO and a pilot signal critical value(PSCOMP)(103). If the strength of PS1x is larger than or equal to the sum of the strength of PSEVDO and PSCOMP, the wireless terminal selects the CDMA2000 1x system(106).

Description

Method for selecting the data call service system for mobile phone with dual mode}

The present invention relates to a method of selecting a data call service system for a dual-mode terminal using a CDMA2000 1x system and an EVDO system. In particular, the CDMA2000 1x system and the EVDO system are installed in the same area, and the two system systems are supported simultaneously. When you want to receive data service of dual-mode wireless terminal as much as possible, select the data service system to prevent the performance degradation of each system in consideration of parameter variables such as load level of each system and received signal strength from each system. In addition, the present invention relates to a method for selecting a data call service system of a dual-mode terminal that provides a good effective (surplus) bandwidth to each data service user.

Early wireless mobile technology began with systems for voice calls.

Since then, due to the demands and technical advances of users using mobile communication services, data communication using 9.6 kbps or 14.4 kbps bandwidth in addition to voice calls is possible using the same system.

Since then, technical development has continued to enable 64.4 kbps data communication, and recently, 144 kbps data communication has become possible.

As described above, it is a standard CDMA2000 1x technology of a synchronous mobile communication system that enables voice communication-oriented wireless communication to 144 kbps-class data communication.

However, the CDMA2000 1x technology does not satisfy advanced data service users who desire higher data broadcasting or transmission speeds, thereby creating a new standard CDMA2000 1x EVolution Data Only or EVolution Data Optimized (EVDO) for data services only.

The standard CDMA2000 1x EVDO supports a much wider bandwidth than the data service bandwidth of CDMA2000 1x.

It supports data rates up to 2.4 Mbps in the forward direction and up to 153.6 Mbps in the reverse direction.

The standard CDMA2000 1x EVDO supports the same frequency band and bandwidth as the CDMA2000 1x standard and can provide a service independently of a system supporting the CDMA2000 1x standard in the same region.

In order to use the above characteristics, a dual-mode wireless terminal using a CDMA2000 1x system and a data service using a CDMA2000 1x system and an EVDO system have emerged in an area receiving both services.

One of the methods of selecting a service system when the terminal wants to receive data service is an EVDO system that attempts to service an EVDO system and, if successful, receives a data service from the EVDO system and fails to provide a service to the CDMA2000 1x system. Priority selection method.

Although the maximum forward data bandwidth of the CDMA2000 1x EVDO system is known as 2.4 Mbps, this is the total bandwidth of the maximum supportable forward data at each base station, and only some of the bandwidths are provided to individual data service users.

The bandwidth provided to the individual data service user or the wireless terminal varies depending on the number of users or wireless terminals in the data service within the service area of each base station and the distance between the base station and the wireless terminal.

If the wireless data user is alone and close to the system in the service area, the total bandwidth provided by the system can be used alone.

However, even when used alone, the service bandwidth is reduced when the distance from the system increases.

In addition, as the number of users using the terminal increases, the bandwidth available to each user gradually decreases, and there is a case that the service cannot be provided because the minimum bandwidth provided by the EVDO is not allocated.

If the first bandwidth is allocated and the service is provided, the effect bandwidth realized by the user due to the interference of other users may be reduced to less than that.

The same phenomenon occurs when the data service user increases in the service area even when the CDMA2000 1x supports the data service alone.

Therefore, in order to provide the user with more wireless channel bandwidth and effective bandwidth as much as possible, the data service should be provided by installing both systems in the same region than the single service of one of the above two systems. .

In addition, when a method of first attempting data service for an EVDO system such as the wireless terminal is used, all data services continuously increase the system load on the EVDO system serving the same region, whereas the CDMA2000 1x system changes the load. And therefore, it is impossible to provide quality service to the data service user.

When a CDMA2000 1x system and an EVDO system both provide services in the same area, and a dual mode wireless terminal capable of supporting both methods is provided with data service, it is not considered to be particular system considering the load of each system. Each database user needs an efficient way to obtain high quality wireless channel bandwidth and effective bandwidth.

In the above-described technology, a conventional CDMA2000 1x system capable of supporting data services based on a voice call service, an EVDO system specialized for a database, and a dual mode wireless terminal interoperable with the systems are provided.

The CDMA2000 1x system is installed in all regions, and a system having a much faster broadcasting or transmission + speed than the CDMA2000 1x system is installed in a part of the region where the CDMA2000 1x system is installed.

In the CDMA2000 1x system and the EVDO system, the total bandwidth that a service can be provided by one base station is limited. As data service users increase in a corresponding area, the bandwidth allocated to each data service user gradually decreases.

The total bandwidth available for service is much better than EVDO systems, which are about six times higher than CDMA2000 1x systems.

In selecting a service system when a dual mode wireless terminal is to receive a data service in the system configuration environment as described above, the determination is performed based on the priority of the wireless terminal without support of the systems.

Therefore, in the related art, a dual mode wireless terminal supporting both a CDMA2000 1x system and an EVDO system has a system acquisition for each of the two systems in an idle state, measurement of the strength of a received signal received from the system, and broadcasting in each system. Monitor system information continuously in a time-division manner.

When the user requests a data service during the idle process, the wireless terminal preferentially requests a data service from an EVDO system that is currently being monitored. If the process fails, the wireless terminal requests a data service from a CDMA2000 1x system that is currently being monitored. .

If the above process fails, it is determined that the data service is not provided.

In the idle process, there is a first case of monitoring only an EVDO system and a second case of monitoring only a CDMA2000 1x system, a third case of monitoring both systems, and a fourth case in which neither system can be monitored.

In the fourth case, the wireless terminal continuously performs system acquisition.

When only the EVDO system is acquired and monitored as in the first case, the wireless terminal attempts a data service request to the EVDO system.

If only the CDMA2000 1x system is acquired and monitored as in the second case, the wireless terminal attempts a data service request to the corresponding CDMA2000 1x system.

When both systems are acquired and monitored as in the third case, the wireless terminal attempts a data service request to the EVDO system.

In the conventional technology as described above, as described in the third case, when the wireless terminals located in the corresponding service area request the data service to the EVDO system, the EVDO system provides the data service and increases the number of users of the data service. The bandwidth that can be allocated is gradually reduced.

Then, the minimum bandwidth provided by the EVDO system can be reduced, and the more users, the smaller the effect bandwidth realized by each user can be.

On the other hand, the CDMA2000 1x system provides no data service so that the load on the system is smaller than that of the EVDO system.

As described above, if the wireless terminal wants to receive data service by preferentially providing the EVDO system, each wireless terminal may not be allocated enough bandwidth, and the quality of the data service may be degraded due to interference by the same system in the same region, and only the EVDO system may be used. By using the data service, there is no load at all with the CDMA2000 1x system and the load is increased only with the EVDO system, and thus the load of each wireless communication system cannot be leveled.

Accordingly, the present invention has been proposed to solve the above-described problems, and is intended to provide a data service of a dual mode wireless terminal in which a CDMA2000 1x system and an EVDO system are installed in the same region and the two systems can simultaneously support the system. When the terminal selects the data service system, it considers the parameter variables such as the load level of each system and the strength of the received signal from each system to prevent the performance degradation of each system and to provide good data effective users. Surplus) The purpose is to provide an effective bandwidth.

In order to achieve the above object, the present invention provides a method for selecting a data call service system by a dual-mode wireless terminal that simultaneously supports a CDMA2000 1x system and an EVDO system.

A service available system determination step of determining which of the systems is a serviceable system;

The received signal strength comparing step of comparing the strengths of the received signals received from each system if both systems are available at the same time as a result of the determination of the serviceable system;

And a forward surplus bandwidth comparison step of selecting an optimal system by comparing the forward subchannel surplus bandwidth and the forward surplus bandwidth of each system according to the received signal strength comparison result.

The present invention also provides a method for selecting a data call service system by a dual-mode wireless terminal that simultaneously supports a CDMA2000 1x system and an EVDO system.

A service available system determination step of determining which of the systems is a serviceable system;

The received signal strength comparing step of comparing the strengths of the received signals received from each system if both systems are available at the same time as a result of the determination of the serviceable system;

A threshold comparison step of comparing a difference between signal strengths of each pilot channel and a signal threshold value of a predetermined pilot channel according to the received signal strength comparison result;

When the service bandwidth is changed by allowing the request of the data call according to the threshold comparison result and allocating a traffic channel,

An additional channel capacity parameter message is added to the CDMA2000 1x system to add an additional channel (SCH) capacity parameter message to predict the forward surplus bandwidth and provide the same to the terminals in the service area.

The present invention also provides a method for selecting a data call service system by a dual-mode wireless terminal that simultaneously supports a CDMA2000 1x system and an EVDO system.

A service available system determination step of determining which of the systems is a serviceable system;

The received signal strength comparing step of comparing the strengths of the received signals received from each system if both systems are available at the same time as a result of the determination of the serviceable system;

A threshold comparison step of comparing a difference between signal strengths of each pilot channel and a signal threshold value of a predetermined pilot channel according to the received signal strength comparison result;

When the service bandwidth is changed by allowing the request of the data call according to the threshold comparison result and allocating a traffic channel,

And adding a forward bandwidth threshold message added to the EVDO system to predict the forward surplus bandwidth and provide it to the terminals in the service area.

If it is determined that only one system can be used as a result of the service available system determination, only the corresponding system is selected.

The received signal strength comparison step may first compare the strength of the signals (PS) of the pilot channel received from each system,

When comparing the signal strength of the pilot channel received from each system,

The difference in signal strength of each pilot channel and the signal threshold of a predetermined pilot channel are compared with each other.

As a result of the determination of the serviceable system, when the predetermined service system is determined, when the forward or reverse bandwidth is changed, the service system is not changed by the terminal.

1 is a flowchart illustrating an operation of determining a service system when establishing a data call of a dual mode wireless terminal according to the present invention.

2 is an additional broadcast message display of the CDMA2000 1x system of the present invention;

3 is an additional broadcast message display of the EVDO system of the present invention.

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

1 is a flowchart illustrating an operation of determining a service system in data call setup of a dual mode wireless terminal according to the present invention, wherein a dual mode wireless terminal capable of supporting a CDMA2000 1x system and an EVDO system is idle from a CDMA2000 1x system. Signal strength of the received pilot channel, forward free bandwidth information of the corresponding system included in the SCH Capability Parameters Message broadcasted on the control channel, and the pilot channel signal received from the EVDO system. Updates to the most recent value while continuously receiving the forward free bandwidth information of the system included in the forward bandwidth threshold message (FRLM) broadcasted on the control channel by the strength and overhead message protocol (OMP Overhead Message Protocol). do.

As shown in FIG. 1, when a user's data call setup request is initiated 100, the wireless terminal first determines in the system selection decision step 101 which system is available for data service.

If only the CDMA2000 1x system is available as the determination result of the system selection determination step 101, it is determined to select 106 the CDMA2000 1x system as the data service system, and only the EVDO system is determined as the determination result of the system selection determination step 101. If available, it is decided to select 107 the EVDO system as the data service system.

If the determination result of the system selection decision step 101 determines that both the CDMA2000 1x system and the EVDO system are capable of data service, the strength of the pilot channel signals PS1 and PSEVDO received from the respective systems is determined. The comparison is made 102 to determine whether is large or small.

As a result of the signal strength comparison determination 102, if the strength of the pilot channel signal PS1x of the CDMA2000 1x system is greater than the strength of the pilot channel signal PSEVDO of the EVDO system (PS1x> PSEVDO), the pilot channel signal (PSEVDO) of the EVDO system is determined. A comparison between the strength of the signal obtained by adding (PSEVDO + PSCOMP) and the strength of the pilot channel signal PS1x of the CDMA2000 1x system to each other is large or small.

When the signal strength comparison determination 102 indicates that the strength of the pilot channel signal PS1x of the CDMA2000 1x system is less than or equal to the strength of the pilot channel signal PSEVDO of the EVDO system (PS1x <= PSEVDO), the CDMA2000 1x system Comparing and determining whether the strength of the pilot channel signal PS1x and the pilot channel signal threshold PSPSP (PSEVDO + PSCOMP) and the strength of the pilot channel signal PSEVDO of the EVDO system are large or small (104).

As a result of the comparison determination 103, the strength of the pilot channel signal PS1x of the CDMA2000 1x system sums the strength of the pilot channel signal PSEVDO of the EVDO system and the threshold value PSCOMP of the pilot channel signal (PSEVDO + PSCOMP). If greater than or equal to the strength of one signal {(PS1x)> = (PSEVDO + PSCOMP)}, it is determined to select 106 the CDMA2000 1x system as the data service system.

As a result of the comparison determination 103, the strength of the pilot channel signal PS1x of the CDMA2000 1x system sums the strength of the pilot channel signal PSEVDO of the EVDO system and the threshold value PSCOMP of the pilot channel signal (PSEVDO + PSCOMP). If smaller than the strength of one signal but greater than the strength of the pilot channel signal PSEVDO of the EVDO system {(PSEVDO) <(PS1x) <(PSEVDO + PSCOMP)}, the forward additional channel (FSCH: Fword SubCHannel) of the CDMA2000 1x system Comparing (105) FSCHRateLimit and FDORateLimit of the EVDO system with each other, it is determined whether the system has more free bandwidth as a service system. Request to provide service.

As a result of the comparison decision 104, the strength of the pilot channel signal PSEVDO of the EVDO system is the sum of the strength of the pilot channel signal PS1x of the CDMA2000 1x system and the threshold value PSCOMP of the pilot channel signal (PS1x + PSCOMP). If it is greater than or equal to the strength of one signal {(PSEVDO)> = (PS1x + PSCOMP), it is decided to select 107 the EVDO system as the data service system.

As a result of the comparison decision 104, the strength of the pilot channel signal PSEVDO of the EVDO system is the sum of the strength of the pilot channel signal PS1x of the CDMA2000 1x system and the threshold value PSCOMP of the pilot channel signal (PS1x + PSCOMP). If less than the strength of one signal but greater than or equal to the strength of the pilot channel signal PS1x of the CDMA2000 1x system {(PS1x) = <(PSEVDO) <(PS1x + PSCOMP)}, The excess bandwidth FSCHRateLimit and the forward free bandwidth FwdRateLimit of the EVDO system are compared to each other to determine whether it is large or small (105).

If the free bandwidth FSCHRateLimit of the forward additional channel of the CDMA2000 1x system is greater than the forward free bandwidth FwdRateLimit of the EVDO system, as a result of the comparison of the forward surplus bandwidth 105, the data service system Determining to select the CDMA2000 1x system (106), and as a result of the comparison of the forward surplus bandwidth (105), the free bandwidth (FSCHRateLimit) of the forward additional channel of the CDMA2000 1x system is the forward free bandwidth (FwdRateLimit) of the EVDO system If less than or equal to {(FSCHRateLimit) <= (FwdRateLimit)}, it is decided to select 107 the EVDO system as the data service system.

In the forward surplus bandwidth comparison determination 105, the surplus bandwidth (FSCHRateLimit) of the forward additional channel of the CDMA2000 1x system is compared with the forward surplus bandwidth (FwdRateLimit) of the EVDO system to have more surplus bandwidth. It is selected as a service system and requests to provide data call service to the system. In this data call service selection procedure, the reverse surplus bandwidth of each system is not considered.

After the service system is determined through the above procedure, the wireless terminal cannot arbitrarily change the service system unless the service system is changed due to a handoff or a traffic channel error.

In addition, the forward or reverse bandwidth required or changed during data service depends on the surplus bandwidth of the service system.

In the above procedure, the free bandwidth FSCHRateLimit of the forward additional channel of the CDMA2000 1x system and the forward free bandwidth FwdRateLimit of the EVDO system, which are compared 105 by the wireless terminal, are information provided by each system.

The CDMA2000 1x system and the EVDO system request and accept a data service by a wireless terminal in a service area, allocate a traffic channel for the data call accordingly, and predict surplus bandwidth whenever the service bandwidth is changed. Broadcast to wireless terminals.

The CDMA2000 1x system uses an SCH Capability Parameters Message as shown in Table 1 including bandwidth information of additional channel capacity as specified in Table 2, such as the additional broadcast message of the CDMA2000 1x system shown in FIG. do.

The EVDO system uses a ForwardRateLimit Message of the EVDO system as shown in Table 3 including surplus bandwidth information as specified in Table 4, such as the additional broadcast message of the EVDO system shown in FIG.

As described above, the present invention selects the service system closer to the wireless terminal by simultaneously considering the signal strength and the traffic load of the pilot channel received from each system when selecting the data call service system of the dual mode wireless terminal. In addition, it is effective to receive a service by allocating a larger bandwidth, and by considering the traffic load of each system, it is possible to distribute the load of the system and to efficiently provide a data service compared to the prior art.

Claims (15)

A method for selecting a data call service system by a dual mode wireless terminal supporting a CDMA2000 1x system and an EVDO system simultaneously, A service available system determination step of determining which of the systems is a serviceable system; The received signal strength comparing step of comparing the strengths of the received signals received from each system if both systems are available at the same time as a result of the determination of the serviceable system; And a forward redundancy bandwidth comparing step of selecting an optimal system by comparing a forward subchannel surplus bandwidth and a forward surplus bandwidth of each system according to the received signal strength comparison result. Selection method. The method according to claim 1, And determining that only one of the systems can be used as a result of the determination of the serviceable system. The method according to claim 1, The received signal strength comparing step of comparing the strength of the signals (PS) of the pilot channel received from each system first, characterized in that the data call service system selection method of the dual-mode terminal. The method according to claim 1 or 3, When comparing the signal strength of the pilot channel received from each system, A method of selecting a data call service system for a dual mode terminal, characterized by comparing the difference in signal strength of each pilot channel with a signal threshold value of a predetermined pilot channel. The method according to claim 1, And determining a service system by a terminal when the bandwidth of the forward or reverse direction is changed after a predetermined service system is determined as a result of the determination of the service capable system. A method for selecting a data call service system by a dual mode wireless terminal supporting a CDMA2000 1x system and an EVDO system simultaneously, A service available system determination step of determining which of the systems is a serviceable system; The received signal strength comparing step of comparing the strengths of the received signals received from each system if both systems are available at the same time as a result of the determination of the serviceable system; A threshold comparison step of comparing a difference between signal strengths of each pilot channel and a signal threshold value of a predetermined pilot channel according to the received signal strength comparison result; When the service bandwidth is changed by allowing the request of the data call according to the threshold comparison result and allocating a traffic channel, The additional channel capacity parameter message is added to the CDMA2000 1x system in order to predict the forward surplus bandwidth and provide it to the terminals in the service area. How to select a data call service system. The method according to claim 6, And determining that only one system can be used as a result of the determination of the serviceable system. The method according to claim 6, The received signal strength comparing step of comparing the strength of the signals of the pilot channel received from each system first data call service system selection method characterized in that. The method according to claim 6 or 8, When comparing the signal strength of the pilot channel received from each system, A method of selecting a data call service system for a dual mode terminal, characterized by comparing the difference in signal strength of each pilot channel with a signal threshold value of a predetermined pilot channel. The method according to claim 6, And determining a service system by a terminal when the bandwidth of the forward or reverse direction is changed after a predetermined service system is determined as a result of the determination of the service capable system. A method for selecting a data call service system by a dual mode wireless terminal supporting a CDMA2000 1x system and an EVDO system simultaneously, A service available system determination step of determining which of the systems is a serviceable system; The received signal strength comparing step of comparing the strengths of the received signals received from each system if both systems are available at the same time as a result of the determination of the serviceable system; A threshold comparison step of comparing a difference between signal strengths of each pilot channel and a signal threshold value of a predetermined pilot channel according to the received signal strength comparison result; When the service bandwidth is changed by allowing the request of the data call according to the threshold comparison result and allocating a traffic channel, A method of selecting a data call service system for a dual mode terminal, comprising the step of adding a forward bandwidth threshold message added to the EVDO system to predict the forward surplus bandwidth and provide it to the terminals in the service area. . The method according to claim 11, And determining that only one system can be used as a result of the determination of the serviceable system. The method according to claim 11, The received signal strength comparing step of comparing the strength of the signals of the pilot channel received from each system first data call service system selection method characterized in that. The method according to claim 11 or 13, When comparing the signal strength of the pilot channel received from each system, A method of selecting a data call service system for a dual mode terminal, characterized by comparing the difference in signal strength of each pilot channel with a signal threshold value of a predetermined pilot channel. The method according to claim 11, And determining a service system by a terminal when the bandwidth of the forward or reverse direction is changed after a predetermined service system is determined as a result of the determination of the service capable system.