Summary of the invention
In view of this, main purpose of the present invention is to provide the method for processing user plane in the handoff procedure, has accelerated switch speed, has reduced to switch the data time-delay that brings, and helps seamlessly transitting in the handoff procedure.
Another object of the present invention also is core net, the base station of realizing the method for processing user plane in the handoff procedure of the present invention is provided, and can improve service transmission quality, accelerates switch speed, effectively guarantees quality of handoff.
For achieving the above object, technical scheme of the present invention is achieved in that
The processing method of user plane in a kind of handoff procedure selects a group node to form the descendant node collection in handoff preparation phase by network side and carry out downlink transfer, and the user terminal uplink downlink is carried out asynchronous switching; This method may further comprise the steps:
After A1, the switching decision, be that each node that descendant node is concentrated distributes identical frequency resource, the radio bearer of transparent transmission is set up in the base station that descendant node is concentrated to the business that user terminal connected;
B1, source base station are after data that core net transmits are provided with time tag, and data forwarding to each base station that descendant node is concentrated, and is disconnected source node and is connected with the descending of user plane;
C1, user terminal down link switch to destination node and forwarding data send finish after, provide the up-downgoing business by destination node for user terminal.
Preferably, step C1 further comprises: the user terminal down link switch to destination node and forwarding data send finish after, packet stops the transparent transmission pattern, target BS is set up the wireless transmission carrying of satisfying network service quality.
Preferably, the frequency resource that descendant node concentrates each node to distribute in the steps A 1 is identical with the frequency resource of source node; Step B1 further comprises: source node rebulids the radio bearer of new transparent transmission, and the radio bearer of described new transparent transmission is identical with the bearing mode of the base station that descendant node is concentrated.
Preferably, step C1 further comprises: core net is that first packet that sends to target BS is provided with the mark that the transmission of indication forwarding data finishes.
Preferably, described network side is base station or radio resources management node RRM Server.
Preferably, descendant node described in the steps A 1 is concentrated and is comprised at least one relaying.
A kind of core net that realizes that the sub-district is switched, comprise network management module, be used to provide being connected of Access Network and external network, the network internal route is managed, support user's mobility, session management, this core net also comprises the data markers module, is used for after the user terminal down link switches, for first packet that sends to target BS is provided with mark.
A kind of base station of realizing that the sub-district is switched comprises resource management module, is used for the user's radio resource management; And data transmission module, be used for node forwarding data to descending set of node; This base station also comprises:
The resource distribution module is used to set up the radio bearer of the identical transparent transmission in each base station of concentrating with descendant node;
The time tag module, the data of changeing before being used to are provided with time tag;
Data management module, after the user terminal path switched to target BS, the downlink data that core net is sent to target BS was stored in the buffer memory of target BS, treated that the data that turn over before source base station send the back that finishes and send.
The processing method of user plane in a kind of handoff procedure selects a group node to form the descendant node collection in handoff preparation phase by network side and carry out downlink transfer, and the user terminal uplink downlink is carried out asynchronous switching; This method may further comprise the steps:
After A2, the switching decision, each node that descendant node is concentrated all is assigned with identical frequency resource, and core net is set up user plane with each base station that descendant node is concentrated and is connected;
B2, core net are after data are provided with time tag, send the above-mentioned data that have time tag simultaneously to source base station and the concentrated base station of descendant node,
After the data that source base station receives before sending the switching decision, disconnection is connected with the down link of user terminal;
After C2, user terminal path switched to target BS, core net stopped to data are provided with time tag, and the described data that are provided with time tag provide the up-downgoing business by destination node for user terminal after sending and finishing.
Preferably, step C2 further comprises: after the described data that are provided with time tag sent and finish, packet stopped the transparent transmission pattern, and target BS is set up the wireless transmission carrying of satisfying network service quality.
Preferably, the frequency resource that descendant node concentrates each node to distribute in the steps A 2 is identical with the frequency resource of source node; Step B2 further comprises: source node rebulids the radio bearer of new transparent transmission, and the radio bearer of described new transparent transmission is identical with the bearing mode of the base station that descendant node is concentrated.
Preferably, described network side is base station or radio resources management node RRM Server.
Preferably, described descendant node is concentrated and is comprised at least one relaying.
A kind of core net that realizes that the sub-district is switched comprises network management module, is used to provide being connected of Access Network and external network, the network internal route is managed support user's mobility, session management; This core net also comprises:
Data transmission module is used for sending data simultaneously to source base station and each concentrated base station of descendant node;
The time tag module is used to above-mentioned data that time tag is set.
Preferably, this core net also comprises:
The time tag administration module after being used for the user terminal path and switching to target BS, stops for sending data time tag being set.
A kind of base station of realizing that the sub-district is switched comprises resource management module, is used for the user's radio resource management, and this base station also comprises:
The resource distribution module is used to set up the radio bearer of concentrating the identical transparent transmission in each base station with descendant node;
Data management module, the metadata cache that is provided with time tag that is used for receiving in buffer area, the data for the treatment of not to be provided with in the source base station buffer memory time tag send finish or overtime after send downwards again.
The present invention passes through to change in the different phase of handoff procedure the downlink transfer pattern of user face data, thereby guarantees can keep data synchronization when a plurality of relayings provide service to a terminal simultaneously, realizes descending grand diversity, brings diversity gain.The present invention has simultaneously reduced switches the data time-delay that brings; And the multipath of downlink data be transmitted in switch finish after, still can in a period of time, keep, help seamlessly transitting in the handoff procedure.
Embodiment
Fig. 1 is a kind of distributed network architecture illustraton of model, system shown in Figure 1 is made up of core net (EPC), one or more base stations (BS), one or more relayings (RN) and at least one user terminal (UE), wherein, be wired connection between EPC and BS and BS and the BS, interface is respectively I
GBAnd I
BBBe wireless connections between BS and RN, RN and UE and BS and the UE, the interface between BS and the RN is I
BRN, the interface between RN and UE and BS and the UE is I
WU
In system shown in Figure 1, EPC is used to provide the linkage function of Access Network and external network, and the route to network internal manages simultaneously, functions such as support user's mobility, session management; BS is used for the management of user's radio resource, sends and receive the data that transmit from UE and RN; RN is a wireless relay nodes, the data that transparent transmission UE, BS and other RN transmit; UE can be attached on the RN, receives the data that transmit from RN, also can directly be attached on the BS, receives the data that transmit from BS.All keep synchronously between each BS, and between each BS, have identical scrambler between the RN.
In above-mentioned system shown in Figure 1, also can not introduce relaying, UE directly is connected with BS.
Fig. 2 is a kind of centrally controlled network framework model figure, system shown in Figure 2 is made up of core net EPC, radio resources management node RRM Server, one or more base station BSs, one or more relayings RN and at least one user terminal UE, wherein, between core net EPC and base station BS, core net EPC and radio resources management node RRM Server and base station BS and the radio resources management node RRMServer is wired connection, and interface is respectively I
GB, I
RGAnd I
RBBe wireless connections between base station BS and relaying RN, relaying RN and user terminal UE and base station BS and the user terminal UE, the interface between base station BS and the relaying RN is I
BRN, the interface between relaying RN and user terminal UE and base station BS and the user terminal UE is I
WUBe wireless connections between radio resources management node RRM Server and the relaying RN, the interface between RRM Server and the RN is I
RRNIn actual applications, whether exist interface not influence the application of this patent between RRMServer and the RN.
In system shown in Figure 2, EPC is used to provide the linkage function of Access Network and external network, and the route to network internal manages simultaneously, functions such as support user's mobility, session management; RRM Server is a center control nodes, manages concentratedly and controls for the Radio Resource of BS; BS is used to send and receive the data that transmit from UE, EPC and RN, the resource of managing RN simultaneously; RN is a wireless relay nodes, the data that transparent transmission UE and BS transmit; UE can be attached on the RN, receives the data that transmit from RN, also can directly be attached on the BS, receives the data that transmit from BS.All keep synchronously between each BS, and between each BS, have identical scrambler between the RN.
In above-mentioned system shown in Figure 2, also can not introduce relaying, UE directly is connected with BS.
Except that existing capability, when user plane adopted the data forwarding mode, EPC involved in the present invention also comprised the data markers module, be used to the user terminal down link to switch after, first packet that sends to target BS is provided with mark.
BS involved in the present invention also comprises the resource distribution module, is used to set up the radio bearer of the identical transparent transmission in each base station of concentrating with descendant node;
The time tag module, the data of changeing before being used to are provided with time tag;
Data management module, during as target BS, after being used for the user terminal path and switching to target BS, the downlink data that core net is sent to target BS is stored in the buffer memory of target BS, treats that the data that turn over before source base station send the back that finishes and send.
Except that existing capability, when user plane adopted the bi-casting mode, EPC involved in the present invention also comprised,
Data transmission module is used for sending data simultaneously to source base station and each concentrated base station of descendant node;
The time tag module is used to above-mentioned data that time tag is set;
The time tag administration module after being used for the user terminal path and switching to target BS, stops for the data that send time tag being set.
BS involved in the present invention also comprises, the resource distribution module is used to set up the radio bearer of the identical transparent transmission in each base station of concentrating with descendant node;
Data management module, the metadata cache that is provided with time tag that is used for receiving in buffer area, the data for the treatment of not to be provided with in the source base station buffer memory time tag send finish or overtime after send downwards again.
Method for processing user plane in the handoff procedure of the present invention is all applicable for two kinds of systems illustrated in figures 1 and 2.
Figure 3 shows that user terminal is switched to the schematic diagram of destination node by source node, this network system comprises user terminal UE, base station BS 1 and base station BS 2..., relaying BS1RN1, BS1RN2 and relaying BS2RN1, BS2RN2 are under the jurisdiction of BS1 and BS2 respectively, user terminal UE can provide service by the base station, also can provide service by relaying.
In actual applications, when user terminal UE was mobile from left to right, user terminal carried out the sub-district and switches the seven kinds of different situations that exist:
First kind of situation, user terminal switches to another base station BS 2 by base station BS 1, and in this case, source node and destination node are the base station;
Second kind of situation, user terminal switches to relaying BS1RN1 or BS1RN2 under the BS1 by base station BS 1, and in this case, source node is the base station, and destination node is a relaying;
The third situation, user terminal switches to base station BS 1 by relaying BS1RN1 or the BS1RN2 under the base station BS 1, and in this case, source node is a relaying, and destination node is the base station;
The 4th kind of situation, user terminal switches to the relaying BS1RN2 that is under the jurisdiction of same base station by relaying BS1RN1, and in this case, source node and destination node are relaying;
The 5th kind of situation, user terminal switches to relaying BS2RN1 or BS2RN2 under another base station BS 2 by base station BS 1, and in this case, source node is the base station, and destination node is a relaying;
The 6th kind of situation, user terminal switches to another base station BS 2 by relaying BS1RN1 or the BS1RN2 under the base station BS 1, and in this case, source node is a relaying, and destination node is the base station;
The 7th kind of situation, user terminal switches to relaying BS2RN1 or BS2RN2 under another base station BS 2 by relaying BS1RN1 under the base station BS 1 or BS1RN2, and in this case, source node and destination node are relaying.
In above-mentioned seven kinds of switch instances, the node that described descendant node is concentrated can be base station and/or relaying.Because the process of the 7th kind of situation is the most complicated, below with the 7th kind of situation--the relaying BS2RN2 that switches under another base station from relaying BS1RN2 is an example, and specific implementation process of the present invention is described.
Be example with the distributed network system (DNS) below, implementation procedure of the present invention when user plane adopts the data forwarding mode is described.
Embodiment one:
In distributed system as shown in Figure 1, terminal initial is linked into BS1RN2, and along with moving of terminal, the wireless connections between UE and the BS1RN2 weaken gradually, trigger handoff threshold, switch to target side BS2RN2 at last.
In this handoff procedure, the changing method flow process as shown in Figure 4, the signaling process of control plane specifically can be referring to another patent application of the applicant, it realizes that thought simply is described below:
(1) source base station BS1 selects target RN set of the suitable RN composition of a combination according to the measuring amount of terminal to report.
(2) each target RN will be configured identical resource.The resource of being distributed can be identical with source base station, also can be different with source base station.
(3) base station that each RN is subordinate in source base station and the target RN set is set up the tunnel respectively, and forwarding data, each base station sends to each RN in the set in the data that preceding switching is received, on the basis that guarantees node and data sync, RN all in the set send identical data to terminal simultaneously, realize the grand diversity of downlink data.
(4) down link kept multipath reception constant after terminal was received switching command, and just up link and source RN was disconnected, and set up wireless connections with target RN.
(5) down link switches to target RN, after EPC executes routing update, target BS notification source base station discharges resource, and the RN that the base station that source base station respectively is subordinate in will notification target RN set stops beyond target RN sends downlink data, and discharges the resource of relevant UE.So far, the up-downgoing business of UE is all supported by target RN.
Processing method when user plane involved in the present invention adopts the data forwarding mode comprises the steps:
Step 1: switch before the decision, downlink data is delivered to source node BS1RN2 by source base station BS1, and send to UE by BS1RN2, the RLC of source, MAC and physical layer configurations are according to the network service quality (QoS of business, Quality of Service) grade, the carrying for its distribution is configured according to network.
Step 2: switch after the decision, BS1 sends resource indication signaling to other BS, receives that all RN after the signaling will be assigned with identical frequency resource, and simultaneously for the business that UE connected, all BS will set up the radio bearer of transparent transmission.
Step 3: after source base station is received the data that transmit from EPC, data forwarding to each target BS, is sent to each RN in the goal set by target BS again.Preceding data of changeing all are provided with time tag, can keep synchronous to guarantee all RN when UE sends data.
Step 4: after target BS was returned resource response message to source base station, user terminal disconnected and being connected with the user plane of source BS1RN2 is descending;
Source BS1RN2 can not participate in the grand diversity of downlink data.The frequency resource that each RN in set this moment distributes can be identical with BS1RN2, also can be different with source base station.
The data that source BS1RN2 also can participate in descending grand diversity with other RN in the set send: source BS1RN2 rebulids the radio bearer of new transparent transmission, and new radio bearer is identical with the bearing mode of other BS.At this moment, the frequency resource that each RN distributed in the set must be identical with BS1RN2.
After finishing above step, the user uplink link keeps and source RN, and source BS connects constant, and downlink data is forwarded to a plurality of BS from source BS, and transparent transmission sends to terminal by RN simultaneously to RN, and end side is then carried out multipath reception.
When carrying out handoff procedure, up link switches to target RN earlier, and down link keeps multipath reception constant; Down link switches to target RN, and after EPC received handoff completion message, execution route switched.Descending route switches to target BS from source BS, being connected and will disconnecting between source BS and the EPC.
Step 5: EPC is that first packet that sends to target BS is provided with mark, is used to indicate forwarding data to send and finishes.
Before will continuing, data in the BS buffer memory of source forward each BS that set RN is subordinate to.The downlink data that EPC sends arrives after the target BS will be in buffer area storage a period of time of target BS, waits for that the data that turn over before the BS of source send in advance.
Step 6: when target BS begins to send first packet that is directly sent by EPC, trigger the resource dispose procedure, target BS will be carried out resource reprovision process simultaneously, and packet stops the transparent transmission pattern, and the QoS of network based business distributes suitable wireless transmission carrying.
Here, the resource dispose procedure is meant: target BS notification source BS discharges resource, and source BS reinforms other BS that are used for macro diversity and discharges resource.
Step 7: switch and finish, the up-downgoing business is all provided by target RN, and business data transmission is by aforementioned definite suitable carrying transmission.
In centrally controlled network system shown in Figure 2, when user plane adopted the data forwarding mode, the present invention was suitable equally, replaced source base station transmission resource indication signaling, reception resource response message to get final product by RRM Server.
Be example with the centrally controlled network system below, implementation procedure of the present invention is described when user plane adopts the bi-casting data mode.
Embodiment two:
In centrally controlled network shown in Figure 2, terminal initial is linked into BS1RN2, and along with moving of terminal, the wireless connections between UE and the BS1RN2 weaken gradually, trigger handoff threshold, switch to target side BS2RN2 at last.
In this handoff procedure, the changing method flow process as shown in Figure 5, the signaling process of control plane specifically can briefly be exactly referring to another patent application of the applicant:
(1) RRM Server selects target RN set of the suitable RN composition of a combination according to the measuring amount of terminal to report.
(2) each target RN will be configured identical resource.The resource of being distributed can be identical with source base station, also can be different with source base station.
(3) RRM Server will notify the ID of the EPC base station that each RN is subordinate to tabulate after each RN in the goal set has been disposed resource, and EPC will send the downlink data of terminals to all base stations in these tabulations, and is sending to each RN by the base station.
(4) down link kept multipath reception constant after terminal was received switching command, and just up link and source RN was disconnected, and set up wireless connections with target RN.
(5) after EPC executes routing update, the base station to target RN place is only sent downlink data, RRM Server notification source base station and other participate in the base station of descending grand diversity, stop to send downlink data to the RN except that target RN, and discharge the resource of relevant UE.So far, the up-downgoing business of UE is all supported by target RN.
Processing method when user plane involved in the present invention adopts the bi-casting mode comprises the steps:
Step 1: switch before the decision, downlink data is sent to source BS1 and is delivered to BS1RN2 by source BS1 by EPC, sends to UE by BS1RN2 again, the RLC of source, MAC and physical layer configurations are according to the QoS grade of business, and the carrying for its distribution is configured according to network.
Step 2: switch after the decision, RRM Servr sends resource indication signaling to other BS, receive that all RN after the signaling will be assigned with identical frequency resource, RRM Server receives after the resource response message that target BS returns to EPC transmit path Indication message, EPC sets up user plane with each target BS and is connected, for the business that UE connected, all BS will set up the radio bearer of transparent transmission simultaneously.
Step 3: EPC is after data are provided with time tag, sends to source base station and target BS simultaneously.Each base station receive after the data that are provided with time tag will be in buffer area buffer memory a period of time, treat the data that receive before the switching decision in the source base station buffer memory send finish or overtime after send downwards again.
Step 4: after the data that source BS1RN2 receives before sending above-mentioned switching decision, disconnection is connected with the down link of terminal;
Source BS1RN2 can not participate in the grand diversity of downlink data.The frequency resource that each RN in set this moment distributes can be identical with BS1RN2, also can be different with source base station.
The data that source BS1RN2 also can participate in descending grand diversity with other RN in the set send: source BS1RN2 rebulids the radio bearer of new transparent transmission, and new radio bearer is identical with the bearing mode of other BS.At this moment, the frequency resource that each RN distributed in the set must be identical with BS1RN2.
When carrying out handoff procedure, up link switches to target RN earlier, and down link keeps multipath reception constant.Then down link switches to target RN, and after RRMServer received handoff completion message, execution route switched.Descending route switches to target BS.
Step 5: after executing the path switching, EPC will stop to downlink data is provided with time tag, be used to indicate the data transmission of the descending grand diversity transmission of needs to finish.
The data that are not provided with time tag arrive behind the target BS can buffer memory a period of time, before waiting in the buffer memory data of free label send finish after, just begin downward transmission.
Step 6: when target BS begins the described data that are not provided with time tag of forwarding step five, RRM Server triggers the resource dispose procedure, target BS triggers radio bearer reprovision process once more simultaneously, stops transparent downward transmission, sets up the radio bearer that satisfies the QoS of survice demand.
RRM Server triggers the resource dispose procedure and refers to, RRM Serve notice other base stations that participate in descending grand diversity except that target BS discharge resource.
Step 7: UE up-downgoing business is all provided by target RN, and business data transmission is by suitable carrying transmission.
For distributed network, user plane adopts the pattern of bi-casting, and the present invention also can be suitable for, and function that above-mentioned RRM Server is relevant and signaling all change source base station into and get final product.
For all the other the six kinds of situations in above-described seven kinds of switch instances, the present invention stands good, and realize simpler: in first kind of switch instances, switch between base station and the base station and carry out, handoff procedure does not have the participation of relaying or does not need the existence of relaying to realize, BS1 directly transmits data to user terminal, and transfer of data all also need not to send indication, Resources allocation to relaying between the base station;
Second and third, in four kinds of situations, switch and all in same base station, carry out, transfer of data only gets final product in base station and affiliated relaying thereof, need not pass through other base stations, user terminal switches to destination node from source node and need not to change former serving base station;
In the 5th kind of sight, switch in the affiliated relay well in source base station and another base station and carry out, the relaying under the source base station does not participate in switching, and need not the relaying under the source base station is carried out resource indication, transfer of data; In the 6th kind of sight, switch between relaying and another base station and carry out, the relaying that need not in another base station participates in, and also need not it is carried out resource indication, transfer of data, Resources allocation.
The above is preferred embodiment of the present invention only, is not to be used to limit protection scope of the present invention.