KR20110043948A - Heterogeneous network handover method and system based on wireless network service zone - Google Patents

Abstract

A heterogeneous network handover method and system based on a wireless network service zone, which enables handover automatically by reflecting macro mobility and related user preference, which is a movement between heterogeneous network services, is proposed. The heterogeneous network method based on the proposed wireless network service zone includes (a) detecting at least one candidate network service available at the user's current location, (b) a metric of the network service and the candidate network service currently being used. Measuring a value, (c) calculating a priority of a network service and a candidate network service currently in use based on the measured metric value, and (d) calculating a calculated priority and a preset user preference. Calculating a handover time point between network services and selecting a candidate network service to be handed over, and (e) a network interface corresponding to the network service currently being used, the network interface corresponding to the network service selected in step (d). The step of changing to.

Description

Heterogeneous network handover method and system based on wireless network service zone {Method and System of Vertical Handover based on Service Zone for Macro Mobility}

The present invention relates to a method and system for heterogeneous network handover based on a wireless network service zone. More particularly, the present invention relates to a wireless network service for changing a network service in consideration of a metric and a user preference of the network service. The present invention relates to a zone-based heterogeneous network handover method and system.

With the rapid development of network technology, users are able to use various network services, and more mobile devices supporting multiple network interfaces are being developed. Due to the development of transportation methods, the speed of movement of users of mobile devices using wireless networks and The range of movement is increasing dramatically. Accordingly, technology development for the vertical handover method for macro mobility, which is the movement between heterogeneous network services, as well as the handover method for the micro mobility moving within the same network service range is emerging as an important issue.

The conventional vertical handover method determines the current network performance based on values such as Received Signal Strength Indication (RSSI), Link Quality Indication (LQI), etc., which are metrics related to network performance from the network hardware interface. The handover point is determined. RSSI and LQI are parameters that can be measured only when supported by the network hardware. There is a problem that the selection of the network hardware interface is limited. In addition, since handover is determined based only on a network performance related metric, a user preference on a user's preference for network service usage such as network service cost (billing), bandwidth, and speed is not considered.

Therefore, there is a need for a technology development for a handover method in a heterogeneous network to solve the problems of the prior art.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a heterogeneous network based on a wireless network service zone that can use an optimal network service at a user's current location when the user moves while using a network service. To provide a handover method and system.

The present invention for achieving the above object is (a) detecting at least one candidate network service available at the user's current location, (b) the metric value of the network service and the candidate network service currently in use (C) calculating the priority of the currently used network service and the candidate network service based on the measured metric value, and (d) based on the calculated priority and a preset user preference. Calculating a handover time point between network services and selecting a candidate network service to be handed over; and (e) converting a network interface corresponding to a network service currently in use into a network interface corresponding to the network service selected in step (d). It is characterized by including the step of changing.

The present invention is characterized in that the current position of the user is calculated through the GPS (Global Positioning System) receiving module.

The present invention is characterized in that step (a) detects a candidate network service using a service support area map of network services corresponding to the network interface.

The present invention is characterized in that the metric value of step (b) measures a round trip time (RTT) and a packet loss rate (PLR) of a network service and a candidate network service currently being used.

In the step (c), the shorter the measured RTT is, the higher the priority is measured, and if the RTT is the same, the smaller the PLR is, the higher the priority is to calculate the priority of the currently used network service and candidate network service. It features one.

According to the present invention, step (d) is performed by subtracting a delay time of changing a network interface corresponding to the network service being handed over from the time point at which the network service currently being used is disconnected for seamless handover. It is characterized by doing.

In the step (d) of the present invention, in the case where there is a candidate network service having a higher user preference than the currently used network service, the priority of the candidate network service is higher than the priority of the currently used network service. It is characterized in that the candidate network service having a selected as a handover target.

According to the present invention, when the priority of a candidate network service having a higher user preference than that of the currently used network service is lower than that of the currently used network service, the present invention is the highest when the difference in priority is within a preset tolerance range. A candidate network service having a user preference may be selected as a handover target.

In the step (d) of the present invention, when the user preference of the candidate network service is lower than the user preference of the currently used network service, if the metric value of the currently used network service exceeds the preset threshold, the candidate When the difference in priority between network services is within a preset allowable range, the candidate network service having the highest user preference may be selected.

In addition, the present invention is a heterogeneous network handover system based on a wireless network service zone, a network service detection module for detecting a candidate network service available at a user's current location, a metric value of a network service and a candidate network service currently being used. A metric measurement module, a priority calculation module that calculates priorities of currently used network services and candidate network services based on calculated metric values, and handover points between network services based on calculated priorities and preset user preferences. A handover point calculation module for calculating and selecting a candidate network service to be handed over, and changing a network interface corresponding to the selected candidate network service to a network interface corresponding to the network service currently being used. And in that it comprises a network interface module and to change at least two or more network interfaces to other features.

The present invention is characterized in that it further comprises a GPS receiving module for calculating the current position of the user.

The present invention is characterized in that the network service detection module detects a candidate network service available at a current location of a user by using a service support area map of the network service.

The present invention is characterized in that the metric measurement module measures the RTT and PLR of the currently used network service and the candidate network service.

According to the present invention, the priority calculation module measures the priority as the measured RTT is short and the priority is higher when the PTT is less when the RTT is the same to calculate the priority of the currently used network service and the candidate network service. It is characterized by doing.

According to the present invention, the handover point calculation module handovers to a candidate network service having the highest user preference when the priority and user preference of the candidate network service are higher than the network service in use, and the priority of the candidate network service is low. Even if it is within the preset allowable range, the mobile station may handover to a candidate network service having the highest user preference.

The present invention is characterized in that the network interface corresponds to different network services.

According to the present invention, when a user moves in an area of a network service (Wireless LAN, WiBro, HSDPA, etc.) that is currently being used, by automatically handing over to an appropriate network service based on network performance and user preferences, The network service can be provided without user intervention, and the metric obtained at the network software level can be used for handover decision making it possible to implement the handover method without being limited to specific network hardware.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

1 is a flowchart of a heterogeneous network handover method based on a wireless network service zone according to an embodiment of the present invention.

A heterogeneous network handover method based on wireless network service zone, comprising: a) detecting at least one candidate network service available at a user's current location, (b) a metric of the network service and candidate network service currently in use measuring a (metric) value, (c) calculating a priority of a currently used network service and a candidate network service based on the measured metric value, (d) a calculated priority and a preset user preference (User) Calculating a handover time point between network services and selecting a candidate network service to be handed over based on a preference; and (e) responding to a network interface selected in step (d) Includes changing to a network interface The.

In step S100 of detecting an available network service, the GPS receiver module 370 is used to calculate a current location of a user who uses a network service, and the network interfaces 360-1 to 360-provided in the device being used by the user. Using the service support area map indicating the service support area of the network service corresponding to n), the candidate network service that is available at the current location of the user and may be a handover target in the future is detected.

In relation to step S110 of measuring a metric value of a network service, a metric in a network service is a cost used to determine a network path. In general, when a network path is set, a router has a least metric value. It will select the path with. In the present invention, RTT (Round Trip Time) and PLR (Packet Loss Rate) values obtained at the software level are used instead of parameters related to network interface hardware as metric values.

In step S110 of measuring a metric value of a network service, a predetermined Internet Control Message Protocol (ICMP) packet is transmitted through a network interface for the currently used network service and the detected available candidate network service. It is desirable to measure RTT and PLR values. ICMP is a protocol that controls messages and reports errors between a host server and an Internet gateway. ICMP transmits packets using ICMP to measure the performance of each network service for the user's current location. The RTT, which is the time from when the response signal is transmitted through the service to the receiving side and then reaches the transmitting side through the network service, is measured, and a PLR indicating how much information is lost in the packet is measured.

Calculating the priority of the network service (S120) compares the measured RTT and PLR to calculate the priority of the network service and the candidate network service currently in use. The higher the performance of the network service at the current location of the user, the smaller the value of the RTT and the PLR is. Therefore, the higher the priority of the network service having the smaller value is calculated. According to an embodiment of the present invention, it is preferable to measure the priority of a network service that takes a shorter time by comparing the RTT value and to measure a higher priority for a network service having a lower PLR value when the RTT value is the same. .

Selecting the handover time and the handover target of the network service (S130) changes the network service based on the calculated priority and user preferences, which will be described in detail with reference to FIGS. 3 and 4. .

In the step S140 of changing a network interface, when a handover is required, the network interface is changed by activating a network interface corresponding to the candidate network service to be changed and deactivating a network interface corresponding to a network service currently being used.

2 is a block diagram of a heterogeneous network handover system 300 based on a wireless network service zone according to an embodiment of the present invention.

The present invention is a heterogeneous network handover system (300) based on a wireless network service zone, comprising: a network service detection module detecting a candidate network service available at a user's current location, a metric value of a network service and a candidate network service currently in use; A metric measurement module for measuring, a priority calculation module for calculating the priority of a network service and a candidate network service currently in use based on the calculated metric value, handover between network services based on the calculated priority and a preset user preference A handover time calculation module for calculating a time point and selecting a candidate network service to be handed over, and changing a network interface corresponding to the currently selected network service to a network interface corresponding to the selected candidate network service And a network interface change module and at least two network interfaces.

In addition, the present invention preferably further includes a GPS receiving module 370 to calculate the current position of the user.

The network service detection module 310 previously stores a service support area map indicating a service support area of a network service corresponding to the network interfaces 360-1 to 360-n provided in the device used by the user. Based on the area map, it detects a candidate network service that can be used at the current location of the user and can be a handover target later.

The metric measurement module 320 transmits a predetermined Internet Control Message Protocol (ICMP) packet through a network interface corresponding to the network service currently in use and a network interface corresponding to the candidate network service, thereby enabling the network service and the candidate network service currently in use. It is desirable to measure RTT and PLR.

ICMP is a protocol that controls messages and reports errors between a host server and an Internet gateway. ICMP transmits packets using ICMP to measure the performance of each network service for the user's current location. RTT, which is the time from when the response signal passes through the service to the receiving side through the network service and reaches the transmitting side, and the PLR indicating how much information is lost in the packet is measured. Know the performance of the target network service.

The priority calculation module 330 compares the measured RTT and PLR to calculate the priority of the currently used network service and the candidate network service. In this case, the smaller the value of the RTT and PLR, the higher the priority of the network service. do. According to an embodiment of the present invention, it is preferable to measure the priority of a network service that takes a shorter time by comparing the RTT value and to measure a higher priority for a network service having a lower PLR value when the RTT value is the same. .

The handover time point calculation module 340 changes the network service based on the priority of the network service and the user preference. This will be described in detail with reference to FIGS. 3 and 4.

The network interface change module 350 activates the network interface corresponding to the target candidate network service when the user's movement requires the handover of the network service, and deactivates the network interface corresponding to the currently used network service. Change the network interface. This enables handover to a new network service.

The network interfaces 360-1 to 360-n correspond to different network services, and the number of all network interfaces is determined by the number provided in the device used by the user. The above-described detection of the network service and the measurement of the metric and priority of the performance of the network service are performed for each network interface.

3 and 4 are flowcharts and diagrams provided to explain a handover method of a network service according to an embodiment of the present invention.

After detecting the user's current location and the candidate network services connectable at the current location (S500), the candidate having a higher user preference than the network service corresponding to the currently used network interface (NI) among the detected candidate network services. First, it is determined whether the network service is available (S505). At this time, the user preference is set according to the user's selection as a criterion for the user's preferred network service such as cost (billing), bandwidth, and speed of the network service.

If there are available candidate network services having a higher user preference than the current network service, it is determined whether there is a candidate network service having a higher priority than the current network service (S510), and the candidate having the highest user preference among the corresponding candidate network services. Handover is performed by changing to a network interface corresponding to a network service (S515).

In addition, even if all of the candidate network services have a lower priority than the current network service, it is determined whether there is a candidate network service corresponding to a difference in priority within a predetermined user's allowable range (S520), and among the corresponding candidate network services. Handover (S515) to the candidate network service having the highest user preference. Through this routine, handover may be performed to a candidate network service within an allowable range even if the user preference is higher than the currently used network service and the priority is higher or lower.

If there are no candidate network services available with higher user preferences than the current network service, it is determined whether RTT and PLR, which are the metric values of the current network service, have a value greater than or equal to a preset threshold (S525). The same routine is executed again from the beginning, and if it is above the threshold, the following routine is continued to change to a candidate network service having a user preference lower than the current network service but having an appropriate priority. Threshold means the value of RTT and PLR that the network service is disconnected or the proper network performance is not guaranteed if the current network service is maintained.

Priority is calculated through the measurement of the RTT and the PLR for the current network service and the candidate network service (S530), and a score value corresponding to the difference between the priority of the current network and the priority of a specific candidate network is obtained. In FIG. 4, the handover timing is determined and the related Diffscore range is shown. The + on the left means the Diffscore value increases and the-on the right means the direction in which the Diffscore value decreases. Where Diffscore is the difference in score values. In other words, the Diffscore value means a difference value between a priority difference between the current network service and a specific candidate network service and a priority difference between the current network service and another specific candidate network service.

When the Diffscore values for two specific candidate network services are reduced and the handover range 730 is approached, the pre-handover routine 710 is executed. Otherwise, the Diffscore values are stored (S540). And run the same routine again from the beginning.

The handover possible range 730 is a range to be handed over, and is set in consideration of the device and environment used by the user. It should be set to the range before reaching, and the handover possible range is calculated by subtracting the delay time for changing the interface to the network interface corresponding to the network service being handed over from the time point at which the network service currently being used is disconnected. It is preferable to set the right boundary of.

In the pre-handover routine 710, the priority is again calculated through the measurement of the RTT and the PLR for the current network service and the candidate network service (S545). Because it keeps changing. In this case, if the Diffscore moves to the right side of FIG. 4 while continuously shrinking, the Diffscore is stored (S555), otherwise the routine is terminated. The reason for saving Diffscore is to know how many times it is shrinking.

It is determined whether or not the diffscore approaches the left boundary of the handover possible range (S560), and if it is still approaching, the pre-handover routine is continued, and if it is approached, the handover routine 720 is started.

In the handover routine 720, the priority is again calculated through the measurement of the RTT and the PLR for the current network service and the candidate network service (S565), and the Diffscore value according to the calculated priority is set in the user preference range for the Diffscore. If it is within the user preference range of Diffscore by comparing the user preference with other candidate network services (S575), if there is another candidate network having a higher user preference, the specific Diffscore value is selected. Terminate the routine for the candidate network service.

The user preference range 740 of Diffscore means an allowable range for selecting candidate network services having higher user preferences regardless of the priority of two specific candidate network services. This is to handover to the candidate network service with higher user preferences.

If Diffscore is not within Diffscore's user preference range (740) or there is no other candidate network service with a higher user preference even if it is in range, then Diffscore is saved (S580) and Diffscore exceeds the right boundary of the handover possible range (730) ( S585) The user preference is changed to a high candidate network service (S590).

If the Diffscore does not exceed the right boundary of the handover possible range, the routine is terminated when the Diffscore moves to the left side of the handover allowable range. Otherwise, the handover routine 720 is repeated again.

Through this process, handover to the network service with the highest user preference is possible while reflecting the metric of network performance.

In addition, with reference to FIG. 3, the threshold value for the current network service, the number of determinations of shrinking of Diffscore, the user preference, the handoverable range related to Diffscore, and the user preference range may be arbitrarily determined according to the device and environment using the network service. .

The invention is not to be limited by the foregoing embodiments and the accompanying drawings, but should be construed by the appended claims. In addition, it will be apparent to those skilled in the art that various forms of substitution, modification, and alteration are possible within the scope of the present invention without departing from the technical spirit of the present invention.

1 is a flowchart of a heterogeneous network handover method based on a wireless network service zone according to an embodiment of the present invention.

2 is a block diagram of a heterogeneous network handover system based on a wireless network service zone according to an embodiment of the present invention.

3 is a flowchart provided to explain a handover method of a network service according to an embodiment of the present invention.

4 is a diagram provided to explain a handover method of a network service according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

Heterogeneous network handover system based on 300 wireless network service zones

310 Network Service Detection Module 320 Metric Measurement Module

330 Priority Calculation Module 340 Handover Point Calculation Module

350 Network Interface Change Module

360-1 to 360-n network interface

370 GPS receiving module

Claims (16)

(a) detecting at least one candidate network service available at the user's current location; (b) measuring a metric value of a network service currently in use and the candidate network service; (c) calculating priorities of the currently used network service and the candidate network service based on the measured metric value; (d) calculating a handover time point between network services and selecting a candidate network service to be handed over based on the calculated priority and a preset user preference; And (e) changing a network interface corresponding to a network service currently in use to a network interface corresponding to the network service selected in step (d); Heterogeneous network handover method based on the wireless network service zone comprising a. The method of claim 1, The current position of the user is a heterogeneous network handover method based on a wireless network service zone, characterized in that calculated via a GPS (Global Positioning System) receiving module. The method of claim 1, The step (a) of the heterogeneous network handover method based on the wireless network service zone, characterized in that the detection of the candidate network service using the service support area map of the network services corresponding to the network interface. The method of claim 1, The metric value of step (b) is a heterogeneous network based on the wireless network service zone, which measures a round trip time (RTT) and a packet loss rate (RTL) of the network service and the candidate network service currently being used. Handover method. The method of claim 4, wherein In the step (c), the shorter the measured RTT is, the higher the priority is measured, and when the RTT is the same, the smaller the PLR is, the higher the priority is to calculate the priority of the currently used network service and the candidate network service. Heterogeneous network handover method based on wireless network service zone. The method of claim 1, In step (d), a handover limit time point is obtained by subtracting a delay time of changing a network interface corresponding to a handovered network service from the time point at which the network service currently being used is disconnected for seamless handover. Heterogeneous network handover method based on wireless network service zone. The method of claim 1, In step (d), if there is the candidate network service having a higher user preference than the network service currently in use, the highest user preference is obtained when the priority of the candidate network service is higher than the priority of the network service currently in use. A heterogeneous network handover method based on a wireless network service zone, characterized in that selecting a candidate network service as a handover target. The method of claim 7, wherein If the priority of the candidate network service having a higher user preference than the currently used network service is lower than the priority of the currently used network service, the highest user preference is obtained when the difference in priority is within a preset allowable range. A heterogeneous network handover method based on a wireless network service zone, characterized in that selecting a candidate network service as a handover target. The method of claim 1, In the step (d), when the user preference of the candidate network service is lower than the user preference of the currently used network service, if the metric value of the currently used network service exceeds the preset threshold, the candidate network service The heterogeneous network handover method based on the wireless network service zone, wherein the candidate network service having the highest user preference is selected when the difference in priority between the two is within a predetermined tolerance range. Heterogeneous network handover system based on wireless network service zone, A network service detection module detecting a candidate network service available at a current location of a user; A metric measurement module for measuring a metric value of a network service currently used and the candidate network service; A priority calculation module for calculating a priority of the currently used network service and a candidate network service based on the calculated metric value; A handover time calculation module for calculating a handover time between network services based on the calculated priority and a preset user preference and selecting a candidate network service to be the handover target; A network interface change module for changing a network interface corresponding to a network service currently in use and a network interface corresponding to the selected candidate network service; And At least two network interfaces; Heterogeneous network handover system based on the wireless network service zone comprising a. The method of claim 10, A GPS receiving module for calculating a current position of a user; Heterogeneous network handover system based on the wireless network service zone further comprising a. The method of claim 10, The network service detection module is a heterogeneous network handover system based on a wireless network service zone, characterized in that it detects candidate network services available at a current location of a user using a service support area map of a network service. The method of claim 10, The metric measuring module measures the RTT and PLR of the currently used network service and the candidate network service. The method of claim 13, The priority calculating module calculates the priority of the network service and the candidate network service currently in use by measuring the priority as the measured RTT is shorter and the priority as the PTT is smaller when the RTT is the same. Heterogeneous network handover system based on wireless network service zone. The method of claim 10, The handover time point calculation module handovers to the candidate network service having the highest user preference when the priority and user preference of the candidate network service are higher than the currently used network service, and even when the priority of the candidate network service is low. Heterogeneous network handover system based on wireless network service zone, characterized in that handover to the candidate network service having the highest user preference within the predetermined allowable range. The method of claim 10, The network interface is a heterogeneous network handover system based on a wireless network service zone, characterized in that each corresponding to a different network service.

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