CN104284344B

CN104284344B - Dispositions method, system and the dual-mode terminal of isolated island Formula V oLTE

Info

Publication number: CN104284344B
Application number: CN201310276538.0A
Authority: CN
Inventors: 杜刚; 熊尚坤; 李文苡; 王庆扬
Original assignee: China Telecom Corp Ltd
Current assignee: China Telecom Corp Ltd
Priority date: 2013-07-03
Filing date: 2013-07-03
Publication date: 2018-05-15
Anticipated expiration: 2033-07-03
Also published as: CN104284344A

Abstract

This disclosure relates to a kind of dispositions method, system and the dual-mode terminal of isolated island Formula V oLTE.This method includes dual-mode terminal in LTE network and overlapping covered interior signal of the reception from LTE and 2G/3G networks at the same time of 2G/3G networks；The audio call initiated in response to dual-mode terminal, receives the information that the base station that dual-mode terminal is currently located in LTE network is sent；Detection dual-mode terminal present position and the loopback delay being currently located between the base station in LTE network；By the loopback delay between dual-mode terminal present position and the base station being currently located in LTE network compared with loopback delay thresholding；If the loopback delay of actual measurement is less than loopback delay thresholding, dual-mode terminal based on VoLTE by call setup on an LTE network, otherwise dual-mode terminal by call setup on 2G/3G networks.The disclosure can ensure relatively low cutting off rate in the case where switching without different system.

Description

Island type VoLTE deployment method and system and dual-mode terminal

Technical Field

The present disclosure relates to mobile communications, and in particular, to a method and a system for deploying an islanding Voice over LTE (LTE Voice over LTE) service, and a dual mode terminal.

Background

LTE (Long Term Evolution) is a Long Term Evolution of UMTS (universal mobile telecommunications System) technical standard established by the 3GPP organization. VoLTE is a voice service system with quality of service guarantees provided by LTE networks.

The LTE network does not realize the whole network coverage in the initial stage of network establishment, and only covers in a limited range; the coverage of the current 2G/3G network, such as GSM (Global System for Mobile communications), WCDMA (Wideband Code Division Multiple Access), CDMA (Code Division Multiple Access), etc., is the full-network coverage. Therefore, from the coverage range, the coverage of the LTE network is only the inner part of the coverage of the 2G/3G network, as shown in fig. 1, the coverage area corresponding to the outermost dark ellipse is the coverage area of the 2G/3G network, and the coverage area corresponding to the inner light ellipse is the coverage area of the LTE network.

In a network formed by overlapping the LTE network and the 2G/3G network, that is, a coverage area corresponding to the light ellipse in fig. 1, a dual-mode terminal supporting both the 2G/3G technology and the LTE technology needs to be used to receive services provided by the two networks.

When the LTE technology does not implement full-network coverage, in order to maintain Continuity when the VoLTE moves from the LTE coverage area to the non-LTE coverage area, a conventional VoLTE deployment scheme is to perform cross-system handover with the 2G/3G network at the edge of the LTE network, as shown in fig. 2, when a user establishes a VoLTE Voice Call in the LTE network and moves to the outside of the LTE coverage area, the LTE network and the 2G/3G network need to jointly start an SRVCC (Single Radio Voice Call Continuity, dual-mode Single-standby wireless Voice Call Continuity) handover mechanism, and the Voice is handed over from the LTE network to the 2G/3G network, thereby ensuring that the Voice Call is not dropped. Voice calls established at the edge of the LTE network are very susceptible to dropped calls if SRVCC technology is not employed.

When the LTE network is switched to the 2G/3G network, signaling interaction between the two networks is required, a neighbor list of the 2G/3G network base station is required to be arranged in the LTE base station, and the dual-mode terminal is required to be capable of searching for networks of different systems according to network signaling while communicating, so that the terminal and the network equipment are extremely complex. Therefore, the existing SRVCC technology has the following technical problems:

(1) the network and the terminal are very complex, so that the application effect of the switching of the different systems is not obvious;

(2) the complexity of the terminal is greatly improved, and the price and the variety of the terminal are influenced;

(3) due to the reasons, it is difficult to deploy the VoLTE technology when LTE is not full-network coverage.

Disclosure of Invention

The present disclosure proposes a new technical solution in view of at least one of the above problems.

The present disclosure provides, in one aspect thereof, a deployment method of islanded VoLTE, which can ensure a lower call drop rate without inter-system handover.

The present disclosure provides, in another aspect thereof, a dual mode terminal capable of guaranteeing a lower dropped call rate without performing inter-system handover.

The present disclosure provides, in yet another aspect thereof, an islanded VoLTE deployment system capable of guaranteeing a low call drop rate without inter-system handover.

According to the present disclosure, there is provided an island VoLTE deployment method, including:

the dual-mode terminal simultaneously receives signals from the LTE network and signals from the 2G/3G network in the overlapping coverage area of the LTE network and the 2G/3G network;

responding to a voice call initiated by a dual-mode terminal, receiving information sent by a base station in an LTE network where the dual-mode terminal is currently located, wherein the information sent by the base station in the LTE network comprises a loopback delay threshold, the loopback delay threshold is related to the position relation between the coverage range of a sector in the LTE network where the dual-mode terminal is currently located and a protective band, and the protective band is an area with a set width from the edge of an overlapping coverage area in the overlapping coverage area of the LTE network and a 2G/3G network;

detecting the loopback time delay between the current position of the dual-mode terminal and a base station in the LTE network;

comparing the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network with a loopback delay threshold;

if the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network is smaller than the loopback delay threshold, the dual-mode terminal establishes the call on the LTE network based on VoLTE, otherwise the dual-mode terminal establishes the call on the 2G/3G network.

In some embodiments of the present disclosure, when the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is partially within the guard band, the loop-back delay threshold sent by the base station in the LTE network where the dual-mode terminal is currently located is adjusted according to the set call drop rate.

In some embodiments of the present disclosure, a loopback delay between a current location of a dual mode terminal and a base station in an LTE network where the dual mode terminal is currently located is detected through an established data link or an access process.

In some embodiments of the present disclosure, the information sent by the base station in the LTE network further includes whether the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is completely within the guard band, and the method further includes:

determining a mode of initiating a call by the dual-mode terminal according to the received information whether the coverage of the sector in the LTE network where the dual-mode terminal is currently located is completely within the guard band;

and if the call is completely within the guard band, the dual-mode terminal establishes the call on the LTE network based on the VoLTE, otherwise, whether the dual-mode terminal supports the VoLTE call is determined according to the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network where the dual-mode terminal is currently located.

In some embodiments of the present disclosure, the width of the guard band is related to the average talk time in the network metrics.

In some embodiments of the present disclosure, the longer the average talk time period in the network metrics, the wider the width of the guard band.

In some embodiments of the present disclosure, the information sent by the base station in the LTE network where the dual-mode terminal is currently located is a system message, a broadcast signal, a multicast signal, or a short message.

According to the present disclosure, there is also provided a dual mode terminal, including:

a network signal receiving unit for simultaneously receiving a signal from the LTE network and a signal from the 2G/3G network in an overlapping coverage area of the LTE network and the 2G/3G network;

a loopback delay threshold receiving unit, configured to receive, in response to a voice call initiated by a dual-mode terminal, information sent by a base station in an LTE network where the dual-mode terminal is currently located, where the information sent by the base station in the LTE network includes a loopback delay threshold, the loopback delay threshold is related to a position relationship between a coverage area of a sector in the LTE network where the dual-mode terminal is currently located and a guard band, and the guard band is an area with a set width from an edge of an overlapping coverage area in an overlapping coverage area of the LTE network and a 2G/3G network;

a loopback delay detection unit for detecting the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network;

a loopback delay comparison unit, configured to compare a loopback delay between a current location of the dual-mode terminal and a base station in the LTE network where the dual-mode terminal is currently located with a loopback delay threshold;

and the call establishing unit is used for establishing the call on the LTE network based on VoLTE if the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network is smaller than the loopback delay threshold, or establishing the call on the 2G/3G network.

In some embodiments of the present disclosure, the loopback delay detection unit detects the loopback delay between the current location of the dual-mode terminal and the base station in the LTE network through the established data link or access process.

In some embodiments of the present disclosure, the information sent by the base station in the LTE network further includes whether the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is completely within the guard band, and the dual-mode terminal further includes:

and the call mode determining unit is used for determining the mode of initiating a call by the dual-mode terminal according to the received information whether the coverage range of the sector in the LTE network where the dual-mode terminal is currently located is completely within the guard band, if so, establishing the call on the LTE network based on VoLTE, otherwise, determining whether the dual-mode terminal supports VoLTE origination according to the loopback delay between the current location of the dual-mode terminal and the base station in the LTE network where the dual-mode terminal is currently located.

According to the disclosure, an island VoLTE deployment system is also provided, which includes LTE network side equipment, 2G/3G network side equipment, and the dual-mode terminal in the foregoing embodiment.

In some embodiments of the present disclosure, when the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is partially within the guard band, the LTE network side device adjusts, according to the set call drop rate, the loopback delay threshold sent by the base station in the LTE network where the dual-mode terminal is currently located.

In the technical scheme of the disclosure, the dual-mode terminal compares the received loopback delay threshold with the measured actual loopback delay of the dual-mode terminal, and if the actual loopback delay is smaller than the threshold, the dual-mode terminal indicates that the terminal is close to the base station and can initiate a VoLTE origination call. In order to ensure a lower call drop rate, the set loopback delay threshold is related to the position relationship between the coverage range of the sector of the dual-mode terminal in the LTE network and the guard band, if the coverage range of the sector of the dual-mode terminal in the LTE network is completely within the guard band, the loopback delay corresponding to the radius of the sector can be used as the loopback delay threshold, and if a part of the coverage range of the sector of the dual-mode terminal in the LTE network is positioned in the guard band, the delay within the guard band corresponding to the distance between the base stations can be used as the loopback delay threshold, so as to ensure a lower call drop rate under the condition of not switching the heterogeneous systems.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, are incorporated in and constitute a part of this application. In the drawings:

fig. 1 is a schematic coverage diagram of an LTE network and a 2G/3G network.

Fig. 2 is a schematic diagram illustrating an implementation of inter-system handover by using SRVCC technology in the prior art.

Fig. 3 is a schematic diagram of the present disclosure setting a VoLTE handover guard band.

Fig. 4 is a schematic diagram of an example handover guard band and sector distribution in the disclosure.

Fig. 5 is a flowchart illustrating a deployment method of islanding VoLTE according to an embodiment of the present disclosure.

Fig. 6 is a schematic diagram of the calculation of the round trip delay of the present disclosure.

Fig. 7 is a flowchart illustrating a deployment method of islanding VoLTE according to another embodiment of the present disclosure.

Fig. 8 is a schematic structural diagram of a dual mode terminal according to an embodiment of the present disclosure.

Fig. 9 is a schematic structural diagram of a dual mode terminal according to another embodiment of the present disclosure.

Fig. 10 is a schematic structural diagram of an islanding VoLTE deployment system according to an embodiment of the present disclosure.

Detailed Description

The present disclosure will be described below with reference to the accompanying drawings. It is to be noted that the following description is merely illustrative and exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. Unless specifically stated otherwise, the relative arrangement of components and steps and numerical expressions and values set forth in the embodiments do not limit the scope of the present disclosure. Additionally, techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail but are intended to be part of the specification where appropriate.

As shown in fig. 3, a switching guard band, i.e., a light gray stripe region in fig. 3, is provided at the edge of the overlapping coverage area of the LTE network and the 2G/3G network (i.e., a white region in the center and a light gray stripe region in the periphery thereof).

Specifically, the width of the guard band may be adjusted according to the set dropped call rate. For example, if it is found that the call drop rate is much lower than the set call drop rate (e.g., 1%) when the guard band in a certain area is within the coverage range of two base stations according to the network index analysis, the width of the guard band may be reduced to the coverage range of one base station, and then it is further verified that the target is reached if the call drop rate can also be lower than 1% when the guard band is within the coverage range of one base station, that is, the width of the guard band may be set to the coverage range of one base station. It is noted that the guard band in the present disclosure may have a width smaller than the coverage of one base station.

Further, the width of the guard band is also related to the average talk time in the network index. The longer the average talk time in the network index, the wider the guard band width.

Because the call duration obeys a certain probability distribution, when the user makes a VoLTE call in a specified area, even if the user moves, most users move to the edge of the LTE network due to the existence of the guard band, and the call is ended. Statistically, 99% of call sessions are within about 600 seconds, and only about 1% of calls may exceed 600 seconds. Therefore, as long as the requirement of 600-second movement of a user can be met, the call drop rate can be limited within 1% and the call quality can meet the requirement of commercial indexes.

In addition, it should be noted that the following embodiments of the present disclosure are not only applicable to voice services, but also applicable to video calls or other mobile communication services. The method is not only suitable for the overlay network of the LTE network and the 2G/3G network, but also suitable for the overlay network formed by any other two mobile communication technologies. Since the coverage area of the newly-built network is smaller than that of the old network in the initial period, and the coverage area of the old network is wider, the embodiments of the present disclosure are applicable to all networks overlapping the new network and the old network.

In order to facilitate description of the technical solution, the following embodiments of the present disclosure take an overlapping network of a CDMA network and an LTE network as an example.

If the CDMA/LTE dual-mode terminal makes a voice call origination in an LTE coverage area, a VoLTE technology or a CDMA voice technology can be adopted, and a VoLTE switching protection band is reserved, so that a sector with a sector coverage area completely within the switching protection band allows the VoLTE origination, such as CELL4 in figure 4. Further, in order to expand the range in which the VoLTE origination can be initiated as much as possible, in fig. 4, the geographical ranges within the arcs of the CELL5 and CELL6 sectors (i.e., the a region of CELL5 and the B region of CELL 6) are allowed to perform VoLTE origination with the base stations of CELL4, CELL5, and CELL6 as the center of a circle, and the LTE network may notify the geographical ranges to the dual-mode terminal through the loopback delay threshold parameter; while geographical areas outside the CELL5 and CELL6 sector arcs do not allow VoLTE origination, voice calls in geographical areas outside the CELL5 and CELL6 sector arcs will employ CDMA voice technology. The geographical range of the LTE sector where the VoLTE call is allowed, that is, the coverage radius of the VoLTE call, can be represented by a round trip delay threshold, and can be notified to the dual-mode terminal by, but not limited to, system message, short message, broadcast, or multicast of the LTE network.

Due to the existence of the switching guard band and the width of the guard band is wide enough, when a user moves in the VoLTE call which is started, even if the user does not switch to the CDMA network, the call drop rate can be low enough, and the commercial network index requirement can be met. The embodiments of the present disclosure described below can maximally deploy VoLTE without full network coverage in an LTE network, and omit a complex process of inter-system handover and network optimization preparation work, thereby significantly simplifying network deployment associated with CDMA and LTE.

As shown in fig. 5, this embodiment may include the steps of:

s502, the dual-mode terminal simultaneously receives signals from the LTE network and signals from the 2G/3G network in the overlapping coverage area of the LTE network and the 2G/3G network, so that the dual-mode terminal which can simultaneously support the LTE network and the 2G/3G network can be accessed into any network.

S504, in response to the voice call initiated by the dual-mode terminal, receive information sent by the base station in the LTE network where the dual-mode terminal is currently located, specifically, the information sent by the base station in the LTE network where the dual-mode terminal is currently located may be a system message, a broadcast signal, a multicast signal, or a short message.

The information sent by the base station in the LTE network includes a loopback delay threshold, where the loopback delay threshold is related to a position relationship between a coverage area of a sector in the LTE network where the dual-mode terminal is currently located and a guard band, and if the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is completely within the guard band, for example, CELL4 shown in fig. 4, the loopback delay corresponding to the radius of the sector may be used as the loopback delay threshold, and if a part of the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is located in the guard band, for example, CELL5 and CELL6 shown in fig. 4, the delay corresponding to the shortest distance between the inner edge of the guard band and the base station may be used as the loopback delay threshold, so as to ensure that users who initiate calls are all located in a VoLTE.

In addition, the guard band is an area with a set width from the edge of the overlapping coverage area in the overlapping coverage area of the LTE network and the 2G/3G network, such as a VoLTE handover guard band shown in fig. 3.

S506, detecting the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network;

for example, the loopback delay between the current location of the dual-mode terminal and the base station in the LTE network can be detected through an established data link or an access process.

As shown in fig. 6, when the idle dual-mode terminal is accessed, the base station determines the loopback delay by using the time difference between the frame timing of the base station and the access information timing sent by the terminal; when the dual-mode terminal is in a service connection state, the dual-mode terminal determines loopback delay according to the time difference between the received downlink frame timing of the base station and the uplink frame timing sent by the terminal, and the uplink frame sending timing of the terminal is adjusted by the base station through a synchronous control command according to the distance between the terminal and the base station.

And S508, comparing the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network with the loopback delay threshold.

S510, if the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network is smaller than the loopback delay threshold, the dual-mode terminal establishes the call on the LTE network based on VoLTE, otherwise, the dual-mode terminal establishes the call on the 2G/3G network.

In this embodiment, the dual-mode terminal compares the received loopback delay threshold with the measured actual loopback delay of the dual-mode terminal, and if the actual loopback delay is smaller than the threshold, it indicates that the terminal is close to the base station, and can initiate a VoLTE origination call. In order to ensure a lower call drop rate, the set loopback delay threshold is related to the position relationship between the coverage range of the sector of the dual-mode terminal in the LTE network and the guard band, if the coverage range of the sector of the dual-mode terminal in the LTE network is completely within the guard band, the loopback delay corresponding to the radius of the sector can be used as the loopback delay threshold, and if a part of the coverage range of the sector of the dual-mode terminal in the LTE network is positioned in the guard band, the delay within the guard band corresponding to the distance between the base stations can be used as the loopback delay threshold, so as to ensure a lower call drop rate under the condition of not switching the heterogeneous systems.

Further, when the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is partially within the guard band, the loopback delay threshold sent by the base station in the LTE network where the dual-mode terminal is currently located may also be adjusted according to the set call drop rate. If the dropped call rate is higher than the network commercial indicator, the loopback delay threshold can be appropriately lowered, i.e., the range of initiating the VoLTE call is reduced, otherwise the loopback delay threshold can be appropriately increased, i.e., the range of initiating the VoLTE call is increased.

As shown in fig. 7, this embodiment may include the steps of:

s702, the dual-mode terminal receives signals from the LTE network and signals from the 2G/3G network simultaneously in the overlapping coverage area of the LTE network and the 2G/3G network.

S704, responding to the voice call initiated by the dual-mode terminal, receiving the information sent by the base station in the LTE network where the dual-mode terminal is currently located; the information sent by the base station in the LTE network comprises a loopback delay threshold and whether the coverage range of a sector in the LTE network where the dual-mode terminal is currently located is completely within a guard band, wherein the loopback delay threshold is related to the position relationship between the coverage range of the sector in the LTE network where the dual-mode terminal is currently located and the guard band.

S706, determining the mode of the dual-mode terminal to initiate the call according to the received information whether the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is completely within the guard band.

S708, if the call is completely within the guard band, the dual-mode terminal establishes the call on the LTE network based on VoLTE, otherwise, S710 is switched to, and whether the dual-mode terminal supports VoLTE origination is determined according to the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network where the dual-mode terminal is currently located.

S710, detecting the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network where the dual-mode terminal is currently located.

And S712, comparing the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network with the loopback delay threshold.

S714, if the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network is smaller than the loopback delay threshold, the dual-mode terminal establishes the call on the LTE network based on VoLTE, otherwise, the dual-mode terminal establishes the call on the 2G/3G network.

In this embodiment, in order to prevent the problem that a sector whose coverage is completely within the guard band cannot initiate a VoLTE origination call at the edge of the sector due to the setting of the loopback delay, the sector whose coverage is completely within the guard band is not judged to be subjected to the loopback delay, but is directly allowed to initiate the VoLTE origination call, and the judgment of the loopback delay is only performed for the sectors whose coverage crosses the guard band, so as to further increase the range in which the VoLTE origination call can be initiated.

Next, referring to fig. 4 again, the technical solution of the present disclosure will be described in detail by a specific example.

The CDMA/LTE dual-mode terminal receives network signals of CDMA and LTE simultaneously in an LTE coverage area;

when a user moves to a position within an arc in CELL5 in the LTE coverage area (i.e., area a), a voice call needs to be made; the base station shared by the three arc sectors is used as a center, the radius can be determined by a loopback delay threshold sent by an LTE network side, if the call drop rate is too high, a small point is allocated to the loopback delay threshold, and if the call drop rate is low, a large point is allocated to the loopback delay threshold;

the dual-mode terminal learns that the call of the sector within a certain radius (namely, an area a in fig. 4) from the base station can be called by the VoLTE origination through the system message of the LTE CELL5, and the radius of the VoLTE origination is allowed by the sector to notify the terminal by the loopback delay threshold parameter;

if the dual-mode terminal is browsing on the internet in the LTE network at this time, the dual-mode terminal has wireless connection, and the dual-mode terminal can be connected to the time difference between downlink frame timing and uplink via an LTE air interface at this time, and determine the loopback delay between the current position of the dual-mode terminal and the base station, as shown in fig. 6, compare the measured loopback delay with the received loopback delay threshold, and the dual-mode terminal knows that the current geographic position can be called by the VoLTE call;

the dual-mode terminal establishes a voice call, and the call is established on the VoLTE technology of the LTE network;

when the user moves to the outside, since the VoLTE handover guard band exists and the guard band width is large enough, the call is not dropped and the voice call ends normally.

If the user continues to move to an area outside the CELL6 arc (i.e. outside the area B in FIG. 4), a voice call needs to be established, at this time, the dual-mode terminal learns from the system information of the sector of the LTE network CELL6 that the call of the sector within a certain radius from the base station can be VoLTE originating call, and the radius of the VoLTE originating call is allowed by the sector to notify the terminal by the loopback delay threshold parameter;

if the dual-mode terminal finishes the internet surfing process at this moment, and therefore, the LTE network is not in wireless connection, the dual-mode terminal initiates an access process to an LTE base station, the base station returns the loopback delay between the terminal and the base station to the dual-mode terminal, the terminal compares the loopback delay obtained by actual measurement with a received loopback delay threshold to obtain that the current geographic position of the dual-mode terminal is beyond the loopback delay threshold allowed by the base station, and therefore VoLTE calling cannot be carried out;

the terminal initiates a request for establishing a voice call in the CDMA network again, and establishes the call on the voice technology of the CDMA network;

the CDMA network is a network with perfect coverage, and the user call is normally ended without call drop.

It will be understood by those skilled in the art that all or part of the steps of implementing the above method embodiments may be implemented by hardware associated with program instructions, the program may be stored in a storage medium readable by a computing device, and the program may execute the steps of the above method embodiments when executed, and the storage medium may include various media capable of storing program codes, such as ROM, RAM, magnetic disk and optical disk.

As shown in fig. 8, the dual mode terminal 80 in this embodiment may include a network signal receiving unit 802, a round trip delay threshold receiving unit 804, a round trip delay detecting unit 806, a round trip delay comparing unit 808, and a call establishing unit 810. Wherein,

a network signal receiving unit 802, configured to simultaneously receive a signal from the LTE network and a signal from the 2G/3G network in an overlapping coverage area of the LTE network and the 2G/3G network;

a loopback delay threshold receiving unit 804, configured to receive, in response to a voice call initiated by a dual-mode terminal, information sent by a base station in an LTE network where the dual-mode terminal is currently located, where the information sent by the base station in the LTE network includes a loopback delay threshold, the loopback delay threshold is related to a position relationship between a coverage area of a sector in the LTE network where the dual-mode terminal is currently located and a guard band, and the guard band is an area with a set width from an edge of an overlapping coverage area in the overlapping coverage area of the LTE network and a 2G/3G network, where the width of the guard band is related to an average talk time in a network index, and the longer the average talk time in the network index, the wider the width of the guard band;

a loopback delay detection unit 806, configured to detect a loopback delay between a current location of the dual-mode terminal and a base station in the LTE network where the dual-mode terminal is currently located;

a loopback delay comparing unit 808, configured to compare a loopback delay between a current location of the dual-mode terminal and a base station in the LTE network where the dual-mode terminal is currently located with a loopback delay threshold;

a call establishing unit 810, configured to establish a call on the LTE network based on VoLTE if a loopback delay between a current location of the dual-mode terminal and a base station in the LTE network is smaller than a loopback delay threshold, otherwise establish the call on the 2G/3G network.

Further, the loopback delay detection unit detects the loopback delay between the current position of the dual-mode terminal and the base station in the current LTE network through the established data link or access process.

Further, the information sent by the base station in the LTE network also includes whether the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is completely within the guard band.

As shown in fig. 9, compared to the embodiment in fig. 8, the dual mode terminal 90 in this embodiment may further include:

a calling mode determining unit 902, configured to determine, according to information that whether a coverage area of a sector in the LTE network where the dual-mode terminal is currently located is completely within a guard band, a mode in which the dual-mode terminal initiates a call, if the coverage area is completely within the guard band, the call is established on the LTE network based on VoLTE, otherwise, whether the dual-mode terminal supports VoLTE origination is determined according to a loopback delay between the current location of the dual-mode terminal and a base station in the LTE network where the dual-mode terminal is currently located.

As shown in fig. 10, the system 100 in this embodiment may include an LTE network-side device 1002, a 2G/3G network-side device 1004, and a dual-mode terminal 1006. Wherein dual mode terminal 1006 can be implemented by the foregoing embodiments.

Further, when the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is partially within the guard band, the LTE network side device adjusts the loopback delay threshold sent by the base station in the LTE network where the dual-mode terminal is currently located according to the set call drop rate.

Further, the information sent by the base station in the LTE network where the dual-mode terminal is currently located is a system message, a broadcast signal, a multicast signal, or a short message.

The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments can be mutually referred to. For the apparatus embodiment, since it is substantially similar to the method embodiment, the description is relatively simple, and reference may be made to the description of the method embodiment section for the relevant points.

While the present disclosure has been described with reference to exemplary embodiments, it should be understood that the present disclosure is not limited to the exemplary embodiments described above. It will be apparent to those skilled in the art that the above-described exemplary embodiments may be modified without departing from the scope and spirit of the disclosure. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. An island VoLTE deployment method, comprising:

responding to a voice call initiated by the dual-mode terminal, receiving information sent by a base station in an LTE network where the dual-mode terminal is currently located, wherein the information sent by the base station in the LTE network comprises a loopback delay threshold, the loopback delay threshold is related to the position relation between a coverage range of a sector in the LTE network where the dual-mode terminal is currently located and a guard band, and the guard band is an area with a set width from the edge of an overlapping coverage area in the overlapping coverage area of the LTE network and the 2G/3G network;

comparing the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network with the loopback delay threshold;

if the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network is smaller than the loopback delay threshold, the dual-mode terminal establishes a call on the LTE network based on VoLTE, otherwise, the dual-mode terminal establishes the call on the 2G/3G network;

if the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is completely in the coverage area of the LTE network except the guard band, taking the loopback delay corresponding to the radius of the sector as the loopback delay threshold;

and if a part of the coverage area of the sector of the LTE network where the dual-mode terminal is located is in the guard band, taking the time delay corresponding to the shortest distance between the edge of the inner side of the guard band and the base station as the loopback delay threshold.

2. The deployment method of islanding VoLTE according to claim 1, wherein when a coverage area of a sector in an LTE network where the dual-mode terminal is currently located is partially within the guard band, a loopback delay threshold sent by a base station in the LTE network where the dual-mode terminal is currently located is adjusted according to a set call drop rate.

3. The island VoLTE deployment method of claim 1, wherein a loopback delay between a current location of the dual mode terminal and a base station in a current LTE network is detected through an established data link or access process.

4. The island VoLTE deployment method of claim 1, wherein the information sent by the base station in the LTE network further includes whether the coverage area of the sector in the LTE network where the dual-mode terminal is currently located is completely within the coverage area of the LTE network except the guard band, and the method further comprises:

determining a mode of initiating a call by the dual-mode terminal according to the received information whether the coverage of the sector of the LTE network where the dual-mode terminal is currently located is completely within the coverage area of the LTE network except the protection band;

and if the terminal is completely positioned in the coverage area of the LTE network except the protection band, the dual-mode terminal establishes a call on the LTE network based on VoLTE, otherwise, whether the dual-mode terminal supports VoLTE origination is determined according to the loopback delay between the current position of the dual-mode terminal and the base station in the LTE network where the dual-mode terminal is currently positioned.

5. The deployment method of islanded VoLTE according to claim 1, wherein the width of the guard band is related to an average talk time in a network index.

6. The island VoLTE deployment method of claim 5, wherein the longer the average talk time in the network metrics, the wider the guard band width.

7. The island VoLTE deployment method of claim 1, wherein the information sent by the base station in the LTE network where the dual-mode terminal is currently located is a system message, a broadcast signal, a multicast signal or a short message.

8. A dual mode terminal, comprising:

a loopback delay threshold receiving unit, configured to receive, in response to a voice call initiated by the dual-mode terminal, information sent by a base station in an LTE network where the dual-mode terminal is currently located, where the information sent by the base station in the LTE network includes a loopback delay threshold, the loopback delay threshold is related to a position relationship between a coverage area of a sector in the LTE network where the dual-mode terminal is currently located and a guard band, and the guard band is an area with a set width from an edge of an overlapping coverage area in an overlapping coverage area of the LTE network and a 2G/3G network;

a loopback delay detection unit, configured to detect a loopback delay between a current location of the dual-mode terminal and a base station in an LTE network where the dual-mode terminal is currently located;

a loopback delay comparison unit, configured to compare the loopback delay between the current location of the dual-mode terminal and the base station in the current LTE network with the loopback delay threshold;

the call establishing unit is used for establishing a call on the LTE network based on VoLTE if the loopback delay between the current position of the dual-mode terminal and a base station in the LTE network is smaller than the loopback delay threshold, otherwise, establishing the call on the 2G/3G network;

and if the coverage area of the sector of the LTE network where the dual-mode terminal is located currently is partially in the guard band, taking the time delay corresponding to the shortest distance between the edge of the inner side of the guard band and the base station as the loopback delay threshold.

9. The dual-mode terminal of claim 8, wherein the loopback delay detection unit detects the loopback delay between the current location of the dual-mode terminal and the base station in the LTE network through an established data link or an access process.

10. The dual-mode terminal of claim 8, wherein the information sent by the base station in the LTE network further includes whether a coverage area of a sector in the LTE network where the dual-mode terminal is currently located is completely within an area of a coverage area of the LTE network except for the guard band, and the dual-mode terminal further includes:

and the call mode determining unit is used for determining a mode of initiating a call by the dual-mode terminal according to the received information whether the coverage range of the sector in the LTE network where the dual-mode terminal is currently located is completely within the area of the coverage area of the LTE network except the guard band, if the coverage range of the sector in the LTE network where the dual-mode terminal is currently located is completely within the area of the coverage area of the LTE network except the guard band, the call is established on the LTE network based on VoLTE, otherwise, whether the dual-mode terminal supports VoLTE calling is determined according to the loopback delay between the current location of the dual-mode terminal and the base station in the LTE network where the dual-mode terminal is.

11. The dual-mode terminal of claim 8, wherein the width of the guard band is related to an average talk time in a network metric.

12. The dual mode terminal of claim 11, wherein the longer the average talk time in the network metrics, the wider the guard band width.

13. An island VoLTE deployment system, comprising LTE network side equipment, 2G/3G network side equipment and the dual-mode terminal of any one of claims 8 to 12.

14. The deployment system of islanded VoLTE according to claim 13, wherein when a coverage area of a sector in an LTE network where the dual mode terminal is currently located is partially within the guard band, the LTE network side device adjusts a loopback delay threshold sent by a base station in the LTE network where the dual mode terminal is currently located according to a set call drop rate.

15. The deployment system of islanded VoLTE according to claim 13, wherein the information sent by the base station in the LTE network where the dual mode terminal is currently located is a system message, a broadcast signal, a multicast signal or a short message.