WO2011063663A1

WO2011063663A1 - Method and device for realizing local switch

Info

Publication number: WO2011063663A1
Application number: PCT/CN2010/076109
Authority: WO
Inventors: 刘强
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-11-30
Filing date: 2010-08-18
Publication date: 2011-06-03
Also published as: CN102083230A; CN102083230B

Abstract

A method and a device for realizing a local switch are provided. The method comprises: a Base Station Control (BSC) obtains the delay time between a first base station, a second base station and the BSC; when the call is switched from a traditional mode into a local exchange mode, the BSC obtains the link delay time from the first base station to the second base station and the link delay time from the second base station to the first base station; the first base station switched delay time can be obtained by subtracting the link delay time from the first base station to the second base station from the delay time between the first base station and the BSC; the second base station switched delay time can be obtained by subtracting the link delay time from the second base station to the first base station from the delay time between the second base station and the BSC; the first base station and the second base station receive the first base station switched delay time and the second base station switched delay time respectively, which can be set into new link parameters. The present invention can improve the situation existing at the local switch that the link time delay difference before and after the link switching is comparatively great.

Description

The present invention relates to the field of communications technologies, and in particular, to a method and apparatus for implementing local switching. BACKGROUND OF THE INVENTION At present, many communication systems use local switching functions. Local exchange refers to the way in which the calling and called users do not go through the core network and directly talk between the two called base stations. The advantage of this operation is that the occupation of the core network resources is reduced, and the transmission delay of the voice is shortened. It saves the use bandwidth of the Abis port (the interface between the base station controller and the base station), and provides convenience for both operators and users. The biggest feature of local switching is that user plane data is no longer transmitted directly between the base stations via the core network. When the call is transmitted in the above manner, it can be considered to be performed in the local exchange mode, and accordingly, the conventional call mode can be described as being performed in the legacy mode. In the local exchange implementation, there is a problem that when the user's voice data (user plane data) is suddenly transferred to the local exchange mode transmission by the traditional mode, there must be a large time difference, resulting in the voice being traditional. When the mode is switched to the local exchange mode, a relatively large loss occurs, and when switching from the local exchange mode to the legacy mode, a large speech overlap occurs. Specifically, as shown in FIG. 1, in the traditional mode, the mobile phone MS I (mobile station) and the mobile phone MS2 make a call. The voice of the mobile phone MS 1 passes through the base station BTS 1 and TC (codec) via the MSC (Mobile Switching Centre) and then the TC to the base station BTS2 to the mobile phone MS2. As can be seen from Fig. 1, after a speech frame is sent from the mobile phone MS 1, it must pass at least T1 + T2. When the call of the mobile phone MS 1 and the mobile phone MS2 is transferred to the local exchange mode, the voice of the mobile phone MS 1 is directly sent to the mobile phone MS2 via the base station BTS1 via the base station BTS1. The time from the mobile phone MS 1 to the MSC after the MSC has arrived at the mobile phone MS2 is much longer than the time between the base station BTS 1 (BTS, Base Station) and the base station BTS2. When the user plane data suddenly changes from one mode to another during a call, a large delay difference may occur due to the transmission link length problem. In the current design of local switching, there is a way to use the base station to maintain two links at the same time before and after the conversion. When the voice sent by the mobile phone enters the local exchange mode from the traditional mode, First, a new link to the other party's BTS is created. After the establishment, the original call link is released, and the conversion to the local exchange mode is completed (the implementation of this local exchange has been proposed in the related patent). At the time of conversion, there is a short moment of 4 ,, the link between the original BTS 1 and the BSC (Base Station Control) in the traditional mode and the link between the newly established base stations BTS 1 and BTS2 in the local exchange mode. Coexistence, and user plane data is sent to both links at the same time. Although these two links coexist, only one is in use. Since the conversion has not been completed, the user hears the voice transmitted from the BTS 1 and BSC links at MS2. However, when the conversion occurs, the link between BTS 1 and BSC will be cut off, and the link between BTS 1 and BTS2 will be enabled. Therefore, the short link will hear the following voice in advance and will be lost. The voice data, thus causing a large segment of voice loss. Conversely, when entering the traditional mode from the local switching mode, the voice transmission link of the former is much shorter than the latter, and for the same reason, a large number of voices are repeatedly heard in the traditional mode. In practical applications, depending on the business needs, it may be frequently converted between the local exchange mode and the traditional mode, which will inevitably bring a bad user experience to the user. At present, in the implementation of local exchange, because the conversion time is relatively short, or the problem is not considered, or a fixed Δ _{t is set} to delay, this method obviously still cannot solve the above problem. The occurrence of this situation is determined by the characteristics of the local exchange, so new solutions must be sought to eliminate the deficiencies of the prior art. SUMMARY OF THE INVENTION The technical problem to be solved by the present invention is to provide a local exchange implementation method and apparatus, which can compensate for voice loss or voice overlap caused by delay difference when converting between a local exchange mode and a legacy mode, and is locally exchanged. Implementation proposes an effective solution to enhance user-risk. In order to solve the above technical problem, the present invention provides a local exchange implementation method, including: when a first terminal and a second terminal establish a call, a base station controller (BSC) establishes a relationship with the first base station and the second base station. The call link, the BSC obtains the delay time between the first base station, the second base station, and the BSC according to the setup time of the call link; when the call is switched from the legacy mode to the local exchange mode, the BSC sends a new link setup message to the a base station and a second base station, obtaining a link delay time of the first base station to the second base station, and a second base station Link delay time to the first base station;

The BSC subtracts the link delay time from the first base station to the second base station according to the delay time between the first base station and the BSC, and obtains the first base station switching delay time; according to the second base station and the BSC Delay time, subtracting the link delay time from the second base station to the first base station, and obtaining a second base station switching delay time;

The BSC sends the release old channel message to the first base station and the second base station, where the old channel message carries the calculated first base station conversion delay time value and the second base station conversion delay time value respectively; the first base station and the second base station The base station receives the first base station switching delay time and the second base station switching delay time respectively, and sets the parameters in the new link, and releases the link between the originally established and the BSC to ensure the first base station and the first The voice packets of the two base stations are sent after delaying the first base station switching delay time and the second base station switching delay time in the new link. Further, the BSC obtains the delay time between the first base station, the second base station, and the BSC according to the setup time of the call link, including:

The BSC records the transmission time of the channel activation message sent to the first base station and the second base station, and the reception time of the channel activation confirmation message sent by the first base station and the second base station; and sends the channel to the first base station and the second base station according to the The sending time of the activation message and the receiving time of the channel activation confirmation message sent by the first base station and the second base station are obtained, and the delay time between the first base station and the BSC and the delay time between the second base station and the BSC are obtained. Further, the link delay time of the BSC to obtain the first base station to the second base station and the link delay time of the second base station to the first base station include:

Obtaining, by the BSC, a link delay time from the first base station to the second base station according to a time interval between sending the first base station link setup message to the new link setup complete message fed back by the second base station; The time interval between the second base station link setup message and the new link setup complete message fed back by the first base station is obtained, and the link delay time of the second base station to the first base station is obtained. Further, the BSC obtains a link delay between the first base station and the second base station according to a time interval between sending the first base station link setup message to the new link setup complete message fed back by the second base station. Time, including:

When the BSC sends a new link setup message to the first base station, the transmission time is recorded; The first base station receives the new link setup message, and starts to initiate the link layer link setup request message to the second base station; after receiving the link setup request message sent by the first base station, the second base station feeds back the new link setup. After the completion message is sent to the BSC, the BSC receives the new link completion message, and records the reception time; the BSC sends a new link setup message to the first base station's transmission time and receives the new link establishment completion message fed back by the second base station. The receiving time is subtracted, and the link delay time from the first base station to the second base station is obtained. Further, the time interval between the second base station and the first base station is obtained according to the time interval between the second base station link setup message sent by the BSC and the new link setup complete message fed back by the first base station. The time includes:

When the BSC sends a new link setup message to the second base station, the transmission time is recorded; the second base station receives the new link setup message, and starts to initiate the link layer link setup request message to the first base station; the first base station receives the first After the link establishment request message sent by the second base station, the new link establishment completion message is fed back to the BSC, and after receiving the new link completion message, the BSC records the reception time;

The BSC subtracts the transmission time at which the new link setup message is sent to the second base station and the reception time at which the new link setup complete message is received by the first base station, and obtains the link delay time from the second base station to the first base station. Further, the new link setup message sent by the BSC to the first base station includes parameters related to the establishment of the link between the first base station, where the parameters include an IP address and a port number, and the BSC sends the new information to the second base station. The link setup message includes parameters related to the link establishment of the second base station, where the parameters include an IP and a port number. Further, the releasing the old channel message sent by the BSC to the first base station includes: releasing link information between the BSC to be released and the first base station, and releasing the old channel message sent by the BSC to the second base station The method includes: link information between the BSC to be released and the second base station. In order to solve the above technical problem, the present invention provides a device for implementing local switching, including: a first delay time obtaining module, a second delay time obtaining module, and a base station switching delay time set in a base station controller (BSC) Obtaining a module, a message sending module, and a processing module disposed at the first base station and the second base station; The first delay time obtaining module is configured to establish, by the first terminal and the second terminal, a call link with the first base station and the second base station when establishing a call, and the BSC obtains respectively according to the establishment time of the call link. a delay time between the first base station, the second base station, and the BSC; the second delay time obtaining module, configured to send the call to the first base station and the second base station when the call is switched from the traditional mode to the local exchange mode a path establishment message, a link delay time from the first base station to the second base station, and a link delay time from the second base station to the first base station; the base station conversion delay time obtaining module, configured to use the first base station and The delay time between the BSCs, minus the link delay time from the first base station to the second base station, to obtain the first base station switching delay time; according to the delay time between the second base station and the BSC, subtracting the second a link delay time from the base station to the first base station, to obtain a second base station switching delay time; the message sending module, configured to send an old channel message to the first base station and the second base station, where the old channel is The information carries the calculated first base station switching delay time value and the second base station switching delay time value respectively; the processing module is configured to receive the first base station switching delay time and the first base station and the second base station respectively The second base station converts the delay time and sets the parameters in the new link, and releases the link between the original established BSC and the BSC to ensure that the voice packets of the first base station and the second base station are respectively extended in the new link. The first base station transition delay time and the second base station conversion delay time are sent. Further, the first delay time obtaining module is further configured to record a sending time of sending a channel activation message to the first base station and the second base station, and receiving a channel activation confirmation message sent by the first base station and the second base station. The receiving time is obtained according to the sending time of the channel activation message sent to the first base station and the second base station, and the receiving time of the channel activation confirmation message sent by the first base station and the second base station, to obtain the first base station and the BSC. Delay time and delay time between the second base station and the BSC. Further, the second delay time obtaining module is further configured to obtain, according to a time interval between sending a message to the first base station link setup message and receiving a new link setup complete message fed back by the second base station, to obtain the first a link delay time from the base station to the second base station; obtaining a second base station to the first time according to a time interval between the BSC transmitting the second base station link setup message to the new link setup complete message received by the first base station The link delay time of the base station. Further, the second delay time obtaining module is further used when the BSC sends a new chain When the path establishes a message to the first base station, the transmission time is recorded; and when the first base station receives the new link setup message, starts to initiate a link layer link setup request message to the second base station, and the second base station receives the first base station. After the sent link setup request message is sent back to the BSC, the BSC receives the new link completion message and records the reception time; sends the BSC to send the new link setup message to the first base station. The time is subtracted from the receiving time of receiving the new link setup complete message fed back by the second base station, and the link delay time of the first base station to the second base station is obtained. Further, the second delay time obtaining module is further configured to: when the BSC sends a new link setup message to the second base station, record the sending time; and when the second base station receives the new link setup message, start to The first base station initiates a link establishment request message of the link layer. After receiving the link setup request message sent by the second base station, the first base station feeds back a new link setup complete message to the BSC, and the BSC receives the new link. After the message, the receiving time is recorded; the sending time of sending the new link setup message to the second base station by the BSC is subtracted from the receiving time of the new link setup complete message fed back by the first base station, and obtaining the second base station to the first The link delay time of the base station. Further, the second delay time obtaining module sends a new link setup message to the first base station, where the first base station includes parameters related to link establishment, where the parameter includes an IP and a port number, and is sent to the first The new link setup message of the second base station includes parameters related to the link establishment of the second base station, where the parameters include an IP and a port number. Further, the releasing the old channel message sent by the message sending module to the first base station includes: releasing link information between the BSC and the first base station, and releasing the old channel message to the second base station The method includes: link information between the BSC to be released and the second base station. The invention greatly improves the situation that the link delay difference before and after the chain switching existing in the local exchange is relatively large. Dynamic and effective adjustments based on actual network. Larger increase in user perception. The invention better compensates for the defects caused by the characteristics of the local exchange, and proposes an effective solution for the realization of the local exchange, which is helpful for improving the customer satisfaction and the conversion performance. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a problem existing in a local exchange process in the prior art. FIG 2 is a flowchart of Δ _t is calculated and transmitted according to the local exchange according to the present invention. 3 is only the effect of Δ _t gen application data in the local exchange according to embodiments of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Between the transition from the local switching mode to the legacy mode, delay due to the link is large, so it is necessary to consider delaying the inter-base station communication with a short transmission delay, so as to ensure that the RTP is guaranteed. (Real Time Transfer Protocol) When the link is converted, there is no user perception abnormality caused by a large delay difference. Usually, it is considered to use a delay empirical value or an estimated value for fixed compensation, which can achieve an improved effect. However, because the location of the base station is different, the delay from the base station to the base station controller may be different. Therefore, if the fixed delay is used, The way of setting is not flexible enough to adapt to different environments and cannot be adjusted automatically. The core idea of the present invention in dealing with this situation is: by performing dynamic compensation of delay on a short transmission link, the local transmission mode has the same transmission delay as the user plane data in the traditional mode, so that When the two modes are converted, they are basically seamlessly connected, avoiding large-scale speech loss or overlap caused by local exchange applications. The present invention is directed to this situation, taking the IP Abis interface as an example, and proposes a new solution to supplement this deficiency. Specifically, the present invention considers the following aspects:

1. Use the delay mechanism to increase the link transmission delay Δ t between the base station and the base station. 2. Specific process design in the base station controller In order to ensure the calculation, the process is designed so that the base station controller can know the delay between the base stations.

3. Dynamic calculation of delay in base station controller

1) Set the delay compensation time Δ _T . Dynamic time Δ _t is calculated. Ensure that adjustments are made based on actual delay conditions.

2) Δ _t is calculated in the BSC, and the BSC estimates the Δ _t according to the report of the establishment of the voice link between the BTS and the BTS, and sends the message to the BTS and the BTS for setting and implementation. 3) two local switching station location may be different, and the transmission delay between the BSC is not the same, thus requiring different compensation Δ _t in the base station uplink RTP link, it is necessary set Δ _t 1, Δ _t 2 performs uplink and downlink compensation separately.

4) A _t is calculated according to the following formula: A t 1= Tl (Abis port delay) -tl (link delay between base stations in BTS 1 to BTS2 direction)

A t 2= T2 (Abis port delay) -t2 (link delay between base stations in BTS2 to BTS 1 direction)

4, the delay provided the base station controller and delivers the calculated time delay Δ _t 1 and Δ t 2 the message sent by the base station. The base station sets up when transmitting. The IPAbis mode is taken as an example to describe the implementation of the technical solution in detail. The method for implementing the local switching according to the present invention includes: when the first terminal and the second terminal establish a call, the base station controller (BSC) Establishing a call link with the first base station and the second base station, and the BSC obtains a delay time between the first base station, the second base station, and the BSC according to the call link setup time; when the call is switched from the traditional mode to the local exchange In the mode, the BSC sends a new link setup message to the first base station and the second base station, and obtains a link delay time of the first base station to the second base station and a link delay time of the second base station to the first base station;

The BSC sends the release old channel message to the first base station and the second base station, respectively, where the calculated first base station conversion delay time and the second base station conversion delay time value are respectively carried; The first base station and the second base station respectively receive the first base station switching delay time and the second base station switching delay time, and are set in the new link parameter, and simultaneously release the link between the originally established and the BSC to ensure The voice packets of the first base station and the second base station are respectively sent after delaying the first base station switching delay time and the second base station switching delay time in the new link. In a preferred embodiment of the present invention, the BSC obtains the delay time between the first base station, the second base station, and the BSC according to the call link setup time, including:

The BSC records the transmission time of the channel activation message sent to the first base station and the second base station, and the reception time of the channel activation confirmation message sent by the first base station and the second base station; and sends a channel activation message according to the first base station and the second base station. The transmission time and the reception time of the channel activation confirmation message sent by the first base station and the second base station, and the delay time between the first base station and the BSC and the delay time between the second base station and the BSC are obtained; In a preferred embodiment of the invention, the BSC obtains the link delay time from the first base station to the second base station and the link delay time from the second base station to the first base station, including:

The BSC obtains a link delay time from the first base station to the second base station according to the new link setup complete message sent to the first base station link setup message, and sends the second base station link according to the BSC. Establishing a message to receive a new link setup complete message fed back by the first base station, and obtaining a link delay time from the second base station to the first base station. In a preferred embodiment of the present invention, the BSC obtains the link extension from the first base station to the second base station according to the new link setup complete message sent to the first base station link setup message and received by the second base station. Time, including:

The BSC records the transmission time when the new link setup message is sent to the first base station; the first base station receives the new link setup message, and starts to initiate the link layer link setup request message to the second base station; the second base station receives the first time. After the link setup request message sent by the base station, the new link setup complete message is fed back to the BSC, and the BSC receives the record receiving time; the BSC sends a new link setup message to the first base station to send the time and receive the second base station. The received time of the feedback of the new link setup complete message is subtracted, and the link delay time of the first base station to the second base station is obtained. In a preferred embodiment of the present invention, the link establishment message is sent to the second base station according to the BSC. Receiving a new link setup complete message fed back by the first base station, and obtaining a link delay time from the second base station to the first base station, including:

The BSC records the transmission time when the new link setup message is sent to the second base station; the second base station receives the new link setup message, and starts to initiate the link layer link setup request message to the first base station; the first base station receives the second After the link establishment request message sent by the base station, the new link establishment completion message is fed back to the BSC, and the BSC receives the record reception time;

The BSC subtracts the transmission time at which the new link setup message is sent to the second base station and the reception time at which the new link setup complete message is received by the first base station, and obtains the link delay time from the second base station to the first base station. In a preferred embodiment of the present invention, the BSC sends a new link setup message to the first base station and the second base station, including parameters related to link establishment, including IP and port number. In a preferred embodiment of the present invention, the release of the old channel message sent by the BSC to the first base station and the second base station respectively includes: a link information between the BSC to be released and the first base station and the second base station. . Figure 2 is a conversion flow and Δ _t calculation of the present invention. Embodiment 1: Design of Local Switching Control Plane Conversion Flow In the present invention, to implement local exchange, three steps need to be implemented: RTP link establishment between base station and base station; RTP link switch between base station and base station controller To the RTP link between the base station and the base station; the release of the RTP link from the base station to the base station controller. Step 1: Establish a new link. The BSC sends a new link message to BTS 1 and BTS2. The establishment of a new link message sent by the BSC to the BTS 1 includes the IP address and port number of the BTS 2. Similarly, the BSC sends the new link message sent in BTS2 to include the IP address and port number of BTS 1. In this way, BTS 1 and BTS2 can know each other and establish an RTP link with the other party. Step 2: The new link setup completion indication. Note that when the BTS 1 activates and sends an RTP link setup request to the BTS2, it does not give the BSC feedback for the new link setup completion indication, but waits until it receives

When the BTS2 sends the RTP link setup request of the BTS 1, the BSC can reply to the BTS 1 for the new link setup completion indication. The processing of BTS2 is the same. The purpose of this is to ensure that the link between BTS 1 and BTS2 is bound to be established during local switching, and that the BSC can calculate BTS 1 and Link delay between BTS2. Step 3: After knowing that the link between BTS 1 and BTS2 is established, the BSC needs to perform Δ tl and Δ _t 2 calculations, and starts to release the link between the original used BSC and BTS 1, BSC and BTS2. Therefore, the BSC sends a release old link message to BTS 1 and BTS 2, respectively, and the contents are the IP address and port number of BTS 1 and BTS 2. This message also carries information Δ _t, the BSC to release the old link message comprising the BTS 1 Δ tl values; message in the BSC to release the old link to BTS2 contains

Δ ί2 value. Thus, similar to the base station informs the phone that the ΤΑ value, the BSC will be informed of the delay compensation Δ _t the base station. Step 4: BTS 1 and BTS2 set the values of Δ tl and Δ _t 2 in the new link parameters, and then release the link between the original established BSC and the BSC. After the release is completed, the message is completed by releasing the old link. Inform the BSC. Embodiment 2: Delay from the traditional mode to the local exchange mode conversion Δ _T 1 and Δ _t 2 Calculation step 1: MS 1 (first terminal) and MS2 (second terminal) When establishing a call, the BSC is giving BTS 1 When the (first base station) and the BTS2 (second base station) transmit the TCH (Traffic Channel) channel activation message 101 and the TCH channel activation message 102, the transmission times T11 and T21 are respectively recorded, and the BSC is established between the BTS and the BTS 1 and the BTS 2 Call link. Step 2: When the BSC receives the channel activation confirmation messages 102 and 202 of the BTS 1 and the BTS 2, respectively, the reception times T12 and T22 are recorded. Therefore, the Abis port delay of TTS=BSC1 and BSC can be calculated as Tl=(T12-T11)/2; likewise, the Abis port delay of BTS2 and BSC is T2=(T22-T21) /2; BSC and BTS 1 at this time The call links between the BTSs and the BTS2 are respectively established. The call begins. Step 3: After the call is established, the two phones switch from the legacy mode to the local exchange mode, and a new link with the base station needs to be established in advance. As shown in FIG. 3, the BSC sends a new link setup message 210 to the BTS2, and The transmission time T23 is recorded. At the same time, a new link setup message 110 is sent to the BTS 1 and the transmission time Τ 13 is recorded. Both messages carry the parameters related to the link establishment of the base station, such as the port, IP, and port (port number). Step 4: After the BTS 1 receives the new link setup message 110, it starts to initiate the link layer to the BTS2. The link establishment request message; Similarly, when the BTS2 receives the new link setup message 210, it starts to initiate a link layer link setup request message to the BTS 1. After receiving the link establishment request message sent by the base station BTS2 (the message indicating the establishment of the link initiation request, which is the link layer internal message), the BTS 1 receives the link establishment message sent by the base station BTS2. After the new link setup complete message 111 is sent to the BSC, the BSC receives the record reception time T14. Similarly, after receiving the link setup request message sent by the base station BTS1 (the message indicating the establishment of the link initiation request, which is the link layer internal message), the BTS2 receives the link establishment link sent by the base station BTS1. After the message, the new link setup complete message 211 is sent to the BSC, and the BSC receives the record reception time T24.

Jt匕, it can be calculated that the link delay t1 from BTS1 to BTS2 is: tl=T13-T24 (from the BSC to the first base station BTS1 to establish a message to the BTS2 feedback base station established message); The link delay t2 of BTS2 to BTS1 is: t2=T23-T14 (from the BSC to the second base station BTS2 setup message to the base station established message received by the BTS1 feedback); Step 5: Calculate Δ tl and Δ _t 2 : ) Δ tl =Tl-tl (when the BSC determines that the two base stations are not the same base station); b)^ t2 = T2- 12 (when the BSC determines that the two base stations are not the same base station); Ο) Δ tl = Tl (BSC when the two base stations is determined for the same base station, at this time tl = 0); d) Δ t 2 = T2 ( BSC determines if the two base stations is the same base station, this time t2 = 0); because Tl, T2, tl, and t2 all contain processing time of other non-link establishment such as codec, so Δtl and Δt2 obtained after subtraction are relatively pure link delay differences. Step 6: BSC and BTS1 to BTS2 are issued to release the old channel messages 112 and 212, respectively, which carry the calculated values of Δ tl Δ and _t 2 are, while also carrying the BSC and BTS to release the Link information between. Step 7: After receiving the values of Δ tl and Δ _t 2 respectively, BTS 1 and BTS 2 are set to the link transmission parameter setting to ensure that the voice packets of BTS 1 and BTS 2 are sent after delays Δ tl and Δ _t 2 respectively. . Embodiment 3: Conversion from local exchange mode to traditional mode Although the conversion direction is opposite to that of the second embodiment, the process is completely identical except for the individual parameter settings. Since the switching direction is from the link between the BTS 1 and the BTS 2 to the link between the BTS and the BSC, when the new link setup message is sent, the built-in parameter is the IP and PORT information of the BSC. This means re-establishing a new link with the BSC. When the old link is released, the BTS 1 and the release are released.

The link between BTS2. At this time, the link delays Δ tl and Δ _t 2 do not need to be recalculated, and the values calculated from the traditional mode to the local switching mode transition (that is, the second embodiment) are still used, and are carried in the release old link message. . Figure 3 describes the application of FIG Δ _t in the local exchange. As can be seen from the figure, after the delays of Δ tl and Δ _t 2 are respectively sent by the BTS 1 and the BTS 2, when the two modes are switched, the seamless transition can be achieved due to the consistent speech delay. This method is not only applicable to IPAbis links, but also applies to Abis links implemented by other protocols. The present invention also provides an apparatus for implementing local switching, comprising: a first delay time obtaining module, a second delay time obtaining module, a base station switching delay time obtaining module, and a message sending set in a base station controller (BSC) a processing module configured in the first base station and the second base station; a first delay time obtaining module, configured to establish, by the first terminal and the second terminal, a call between the first base station and the second base station when establishing a call a link, the BSC obtains a delay time between the first base station, the second base station, and the BSC according to the setup time of the call link, and a second delay time obtaining module, configured to switch the call from the traditional mode to the local exchange mode, Sending a new link setup message to the first base station and the second base station, obtaining a link delay time from the first base station to the second base station, and a link delay time from the second base station to the first base station; a base station switching delay time obtaining module, configured to subtract a link delay time of the first base station to the second base station according to a delay time between the first base station and the BSC, to obtain a first base station switching delay time; The delay time between the second base station and the BSC, minus the link delay time of the second base station to the first base station, to obtain the second base station switching delay time; the message sending module, configured to the first base station and the second base station The old channel message is respectively delivered, where the old channel message carries the calculated first base station switching delay time and the second base station switching delay time value respectively; the processing module is set at the first base station and the second base station, respectively received The first base station switching delay time and the second base station switching delay time are set in the parameters of the new link, and simultaneously release the link between the originally established and the BSC to ensure the voices of the first base station and the second base station. The packet is sent after delaying the first base station switching delay time and the second base station switching delay time in the new link. In a preferred embodiment of the present invention, the first delay time obtaining module is further configured to record a transmission time of transmitting a channel activation message to the first base station and the second base station, and receive a channel sent by the first base station and the second base station. a receiving time of the activation confirmation message; obtaining the first base station and the BSC according to the sending time of the channel activation message sent to the first base station and the second base station, and the receiving time of the channel activation confirmation message sent by the first base station and the second base station The delay time between the delay time and the delay between the second base station and the BSC. In a preferred embodiment of the present invention, the second delay time obtaining module is further configured to: according to the time interval between the message sent to the first base station link setup message and the new link setup complete message fed back by the second base station Obtaining a link delay time from the first base station to the second base station; obtaining a second time according to a time interval between the BSC sending the second base station link setup message to the new link setup complete message received by the first base station feedback The link delay time from the base station to the first base station. In a preferred embodiment of the present invention, the second delay time obtaining module is further configured to: when the BSC sends a new link setup message to the first base station, record the transmission time; and when the first base station receives the new link setup message And starting to initiate a link establishment link setup request message to the second base station, and after receiving the link setup request message sent by the first base station, the second base station feeds back a new link setup complete message to the BSC, and the BSC receives the new message. After the link completion message, the reception time is recorded; the transmission time of the BSC transmitting the new link setup message to the first base station is subtracted from the reception time of the new link setup complete message fed back by the second base station, and the first base station is obtained. The link delay time to the second base station. In a preferred embodiment of the present invention, the second delay time obtaining module is further configured to: when the BSC sends a new link setup message to the second base station, record the transmission time; and when the second base station receives the new link establishment The message starts to initiate a link establishment link request message to the first base station, and after receiving the link setup request message sent by the second base station, the first base station feeds back a new link setup complete message to the BSC, and the BSC receives the message. After the new link completes the message, and records the receiving time; the sending time at which the BSC sends the new link setup message to the second base station is subtracted from the receiving time of the new link setup complete message fed back by the first base station, and obtains the second The link delay time from the base station to the first base station. In a preferred embodiment of the present invention, the second delay time obtaining module sends a new link setup message to the first base station, including parameters related to the link establishment of the first base station, parameters including IP and port numbers, and sending The new link setup message to the second base station includes parameters related to the link establishment of the second base station, where the parameters include an IP and a port number. In a preferred embodiment of the present invention, the release old channel message sent by the message sending module to the first base station and the second base station includes: link information between the BSC to be released and the first base station, to the second base station The released old channel message includes: link information between the BSC to be released and the second base station. It will be apparent to those skilled in the art that various modifications and variations can be made in the method of the invention without departing from the spirit and scope of the method. Thus, it is intended that the present invention cover the modifications and modifications of the invention The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Those skilled in the art should be able to associate with other mobile communication systems, such as PHS (Personal Handy Phone System), CDMA (Code Division Multiple Access) or some 3G mobile communication systems, etc., which should belong to the present invention. Within the scope of protection. The above-described embodiments are described in the preferred embodiments, but are merely illustrative of the invention and are not intended to limit the scope of the invention. Also, various possible equivalents and modifications may be made without departing from the scope of the invention as defined by the appended claims.

Claims

Claims A method of local exchange implementation, characterized in that it comprises:

When the first terminal and the second terminal establish a call, the base station controller BSC establishes a call link with the first base station and the second base station, and the BSC obtains the respectively according to the establishment time of the call link. Delay time between the first base station, the second base station, and the BSC; when the call transitions from the legacy mode to the local exchange mode, the BSC sends a new link setup message to the first base station and the first a second base station, obtaining a link delay time of the first base station to the second base station, and a link delay time of the second base station to the first base station; the BSC according to the first base station a delay time between the BSCs, minus a link delay time of the first base station to the second base station, to obtain a first base station switching delay time; according to the second base station and the BSC The delay time between the second base station and the first base station is subtracted, and the second base station switching delay time is obtained;

And the BSC sends the release old channel message to the first base station and the second base station, where the old channel message respectively carries the calculated first base station conversion delay time value and the second base station Conversion delay time value;

Receiving, by the first base station and the second base station, the first base station switching delay time and the second base station switching delay time, respectively, and setting the parameters in the new link, and releasing the originally established sum a link between the BSCs;

The voice packets of the first base station and the second base station are sent after delaying the first base station switching delay time and the second base station switching delay time in the new link, respectively. The method according to claim 1, wherein the delay time between the first base station, the second base station, and the BSC is obtained by the BSC at the settling time of the call link, respectively:

And sending, by the BSC, a transmission time of the channel activation message to the first base station and the second base station, and receiving a receiving time of the channel activation confirmation message sent by the first base station and the second base station;

Transmitting a transmission time of the channel activation message to the first base station and the second base station, and receiving a channel activation confirmation message sent by the first base station and the second base station Receiving time, obtaining a delay time between the first base station and the BSC and a delay time between the second base station and the BSC.

The method according to claim 1, wherein the BSC obtains a link delay time of the first base station to the second base station and a chain of the second base station to the first base station The road delay time includes:

Obtaining, by the BSC, a link delay between the first base station and the second base station according to a time interval between sending a first base station link setup message and receiving a new link setup complete message fed back by the second base station Obtaining, according to a time interval between the second base station link setup message sent by the BSC and receiving a new link setup complete message fed back by the first base station, obtaining the second base station to the first base station Link delay time.

The method according to claim 3, wherein the time interval between the BSC sent to the first base station link setup message and the new link setup complete message fed back by the second base station is obtained. The link delay time from the first base station to the second base station includes:

When the BSC sends a new link setup message to the first base station, the transmission time is recorded; the first base station receives the new link setup message, and starts to initiate a link layer link to the second base station. Establishing a request message; after receiving the link setup request message sent by the first base station, the second base station feeds back a new link setup complete message to the BSC, and the BSC receives the new link. After completing the message, and recording the receiving time;

Determining, by the BSC, the sending time of the new link setup message to the first base station and the receiving time of receiving the new link setup complete message fed back by the second base station, to obtain the first The link delay time from the base station to the second base station.

5. The method according to claim 3, wherein: - a time interval between the BSC sending the second base station link setup message to the new link setup complete message fed back by the first base station And obtaining a link delay time from the second base station to the first base station, where

When the BSC sends the new link setup message to the second base station, the transmission time is recorded;

Receiving, by the second base station, the new link setup message, initiating a link establishment link request message to the first base station; the first base station receiving the After the link establishment request message, the new link establishment completion message is fed back to the BSC, and after receiving the new link completion message, the BSC records the reception time; Transmitting, by the BSC, a sending moment of sending the new link setup message to the second base station to a receiving moment of receiving the new link setup complete message fed back by the first base station, to obtain the second The link delay time of the base station to the first base station.

The method according to claim 1, wherein the new link setup message sent by the BSC to the first base station includes parameters related to link establishment of the first base station, where The parameter includes an IP and a port number, and the new link setup message sent by the BSC to the second base station includes parameters related to link establishment of the second base station, where the parameters include IP and The port number.

The method according to claim 1, wherein the releasing the old channel message sent by the BSC to the first base station comprises: a chain between the BSC to be released and the first base station The information about the old channel that is sent by the BSC to the second base station includes: link information between the BSC to be released and the second base station.

8. The device implemented by the local exchange, comprising: a first delay time obtaining module, a second delay time obtaining module, a base station switching delay time obtaining module, and a message sending module, which are set in the base station controller BSC And a processing module that is configured by the first base station and the second base station; and the first delay time obtaining module is configured to establish, when the call is established, the first terminal and the second terminal, a call link between the second base stations, where the BSC obtains a delay time between the first base station, the second base station, and the BSC according to the setup time of the call link;

The second delay time obtaining module is configured to: when the call is switched from the traditional mode to the local switching mode, send the new link setup message to the first base station and the second base station, to obtain the first base station to the a link delay time of the second base station and a link delay time of the second base station to the first base station;

The base station switching delay time obtaining module is configured to: subtract, according to a delay time between the first base station and the BSC, a link delay time of the first base station to the second base station, to obtain Decoding a delay time of the first base station; subtracting a link delay time of the second base station to the first base station according to a delay time between the second base station and the BSC, to obtain a second base station conversion Delay time

The message sending module is configured to send a release old channel message to the first base station and the second base station, where the old channel message carries the calculated first base station conversion delay time value and Translating a delay time value by the second base station; The processing module is configured to receive, by the first base station and the second base station, the first base station switching delay time and the second base station switching delay time, and set parameters of the new link And releasing the link between the originally established BSC and the BSC to ensure that the voice packets of the first base station and the second base station respectively delay the first base station in the new link. The time is transmitted after the second base station transition delay time.

9. Apparatus according to claim 8 wherein:

The first delay time obtaining module is further configured to record a sending time of sending a channel activation message to the first base station and the second base station, and receiving a channel sent by the first base station and the second base station The receiving time of the activation confirmation message;

And the receiving time of the channel activation message sent by the first base station and the second base station, and the receiving time of the channel activation confirmation message sent by the first base station and the second base station, a delay time between a base station and the BSC and a delay time between the second base station and the BSC.

10. Apparatus according to claim 8 wherein:

The second delay time obtaining module is further configured to obtain, according to a time interval between sending a message to the first base station link setup message and receiving a new link setup complete message fed back by the second base station, to obtain the first base station to a link delay time of the second base station; obtaining, according to a time interval between the BSC sending the second base station link setup message to the new link setup complete message fed back by the first base station, The link delay time of the second base station to the first base station.

11. Apparatus according to claim 10 wherein:

The second delay time obtaining module is further configured to: when the BSC sends a new link setup message to the first base station, record a transmission time; and when the first base station receives the new link establishment a message, starting to initiate a link establishment link request message to the second base station, where the second base station receives the link setup request message sent by the first base station, and the feedback new link is established. When the message is sent to the BSC, the BSC receives the new link completion message, and records the reception time; the BSC sends the new link setup message to the first base station to send the time and receive the message. The receiving time of the new link setup complete message fed back by the second base station is subtracted, and the link delay time of the first base station to the second base station is obtained.

12. Apparatus according to claim 10, wherein The second delay time obtaining module is further configured to: when the BSC sends the new link setup message to the second base station, record a sending moment; and when the second base station receives the new chain And establishing a link establishment request message of the link layer to the first base station, where the first base station receives the link establishment request message sent by the second base station, and feeds back a new link. After the completion message is sent to the BSC, the BSC receives the new link completion message, and records the reception time; and sends the new link setup message to the second base station by the BSC. The receiving time of the new link setup complete message fed back by the first base station is subtracted, and the link delay time of the second base station to the first base station is obtained.

13. Apparatus according to claim 8 wherein:

The new link setup message sent by the second delay time obtaining module to the first base station includes parameters related to link establishment of the first base station, where the parameter includes an IP and a port number. The new link setup message sent to the second base station includes parameters related to link establishment of the second base station, where the parameters include an IP and a port number.

14. Apparatus according to claim 8 wherein:

The releasing the old channel message sent by the message sending module to the first base station includes: releasing the link information between the BSC and the first base station, and releasing the information to the second base station The old channel message includes: link information between the BSC to be released and the second base station.