CN108076481B

CN108076481B - Method for terminal to access cluster group calling later

Info

Publication number: CN108076481B
Application number: CN201610988758.XA
Authority: CN
Inventors: 万欢根; 杨洁
Original assignee: Potevio Information Technology Co Ltd
Current assignee: Potevio Information Technology Co Ltd
Priority date: 2016-11-10
Filing date: 2016-11-10
Publication date: 2021-05-14
Anticipated expiration: 2036-11-10
Also published as: CN108076481A

Abstract

The invention provides a method for a terminal to access cluster group calling later, which comprises the following steps executed in a CP of a base station ENB: when an event that a terminal accesses to the cluster group calling later is detected, the terminal completes the later access process of the terminal in cooperation with UP of the base station ENB; and after the UP sends a first message indicating that the late access process is completed to the terminal, sending a second message for transferring the state of a compression party maintained by the UP from the current compression stable state to the compression initial state to the UP. Through a late access process initiated by the ENB, the state of the UP compression party is transferred from a compression stable state to a compression initial state, so that the terminal access cluster group can successfully decompress the business data at the first time after receiving the business data, and the influence of the loss of the data caused by the failure of the decompression on the late access speed is avoided.

Description

Method for terminal to access cluster group calling later

Technical Field

The invention relates to the technical field of mobile communication, in particular to a method for a terminal to access cluster group calling later.

Background

In the LTE cluster system, the PDCP protocol adopts an ROHC head compression technology to compress an IP series head corresponding to a PDCP SDU in the group calling service.

The ROHC rationale is: utilizing the change rules of various fields in the IP series header and classifying the fields according to the difference of the change rules; most fields are unchanged in data stream, and can be directly compressed after initialization transmission is finished without being put into a compressed message, only a few fields are continuously changed, a compression coding method is required to be used, and then, the selection of the type of the compressed message is determined.

Generally, the compression party selects IR messages in the initial compression state (IR state), and in the group call service, in order to obtain a better compression rate, the compression party enters the stable compression state (SO state) and then selects UO-0 messages.

For the decompressor, firstly receiving the decompressed IR message, establishing context by the decompression result when decompressing the IR message, and storing the header reference information; when receiving UO-0 message and decompressing, adding increment information carried in the message based on the established context, thereby decompressing the original message.

However, the group call service is unidirectional downlink and has no feedback channel, so the ROHC can only operate in the U mode (unidirectional mode). Thus, when the ROHC operates in the U mode, there is no feedback processing method, and in the prior art, in order to ensure the robustness of the compression method and enable the decompressor (or the receiver) to perform the correct decompression processing, the compressor (or the sender) performs a periodic header update processing, that is, the compressor periodically transitions the compression state.

Thus, as shown in fig. 1, after the late access timer of the trunking system is overtime, the base station sends a group call establishment request message at the air interface, SO that the trunking UE joins the trunking group call midway in the group call service, at this time, as shown in fig. 2, if the compression party sends a UO-0 message in the SO state, and the trunking UE newly joining the trunking group call has not yet established a complete context, it will cause a decompression failure to decompress the UO-0 message. And the UE newly added into the cluster combination can decompress the IR message only after the compression party periodically returns to the IR state to send the IR message, and establishes a context to successfully decompress the IR message. However, in all data from the SO state of one period to the IR state of the next period of the compression party, the UE newly added to the cluster fails to decompress and discards the data, SO that the UE cannot listen to the group call service in time after a delay, and the user perception is affected due to an excessive delay.

In view of the above, the present invention provides a method for a terminal to access a group call late, so as to improve the late access speed of a group UE, eliminate the phenomenon of discarding data due to decompression failure, and improve the group user perception.

Disclosure of Invention

The invention provides a method for a terminal to access cluster group calling later, which is characterized in that through a later access process initiated by an ENB, the UP compression side state of the ENB of a base station is transferred from a compression stable state to a compression initial state, so that the terminal can be successfully decompressed in the first time after being accessed, and the influence of data loss caused by decompression failure on the later access speed is avoided.

The invention provides a method for a terminal to access cluster group calling later, which comprises the following steps executed in a CP of a base station ENB:

when an event that a terminal accesses to the cluster group calling later is detected, the terminal completes the later access process of the terminal in cooperation with UP of the base station ENB;

and after the UP sends a first message indicating that the late access process is completed to the terminal, sending a second message for transferring the state of a compression party maintained by the UP from the current compression stable state to the compression initial state to the UP.

Optionally, whether an event that the terminal accesses the trunking group call later occurs is determined by detecting whether the late access timer is overtime.

Optionally, the first message is a traversing Paging message and a Group Call Config message.

Optionally, the second message is sent by invoking RRM of the base station ENB.

Optionally, the second message is an ROHC compressor state initialization indication message maintained by the UP.

The invention also provides a method for the terminal to access the cluster group calling later, which comprises the following steps executed in the UP of the base station ENB:

when a late access process of a terminal is completed in cooperation with a CP of the ENB, sending a first message indicating that the late access process is completed to the terminal;

and after the first message is sent to the terminal, receiving a second message sent by the CP, and transferring the maintained state of the compression party from the current compression stable state to the compression initial state according to the second message.

Optionally, the second message is sent by the CP by invoking RRM of the base station ENB.

Optionally, the method further comprises performing, at the UP of the base station ENB, the steps of:

when the state of a compression party is transferred from a compression stable state to a compression initial state, a CO message of compressed data sent to a terminal accessing the cluster group call is switched to an IR message;

when the number of the IR messages continuously sent reaches a preset value, the state of the maintained compression party is transferred to a compression stable state from the current compression initial state;

and when the state of the compression party is transferred from the compression initial state to the compression stable state, switching the IR message of the compressed data sent to the terminal accessing the cluster group call into a CO message.

Drawings

Fig. 1 is a schematic diagram of a terminal late accessing to a group call in the prior art;

fig. 2 is a schematic diagram of a compression processing mechanism after a terminal accesses a group call later in the prior art;

FIG. 3 is a flow chart of a method performed at a CP of a base station ENB according to the present invention;

FIG. 4 is a flow chart of the method of the present invention performed at the UP of the base station ENB;

fig. 5 is a schematic diagram of a group call that a terminal accesses later to a cluster according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a compression processing mechanism after a terminal accesses a group call late according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

As can be seen from fig. 1 and fig. 2, for the group call service in the LTE trunking system, when the decompression method of the ROHC header compression technology is used, and when the compressed data encapsulated in the IR packet is decompressed in the initial state of compression, a context is established according to the decompression result, so that the original header reference information is stored in the decompression party of the terminal, and when the compressed data is restored in the initial state of non-compression, the original header reference information in the context needs to be relied on. In this way, when the decompressor of the terminal receives compressed data in another compressed message, the decompressor can correctly perform decompression processing based on the context.

In the non-compressed initial state, the compressed data is encapsulated in a CO message, wherein the CO message can be any one of a UO-0 message, a UO-1-ID message, a UO-1-TS message, a UOR-2-ID message and a UOR-2-TS message. A UO-0 message is usually used, and in the specific embodiment, the UO-0 message is taken as an example for explanation, and when other messages are sent, the scheme taking the UO-0 message as an example can be referred to.

Fig. 3 shows a method for a terminal to access a group call late, where fig. 3 is a flowchart executed by a CP of a base station ENB in the method provided by the present invention.

The method comprises the following steps executed at the CP of the ENB:

301. when an event that a terminal accesses to the cluster group calling later is detected, the terminal completes the later access process of the terminal in cooperation with UP of the base station ENB;

in the present invention, the base station ENB serves as a compression side including CP and UP. The terminal UE acts as the decompressor. The group calling service is a unidirectional downlink channel without a feedback channel. In the group calling service, there is an event that the cluster terminal UE accesses late and joins in the group calling service midway. The CP and the UP are required to cooperatively access the terminal UE to the group call service later, so that the terminal UE can receive the message sent by the compression party.

302. And after the UP sends a first message indicating that the late access process is completed to the terminal, sending a second message for transferring the state of a compression party maintained by the UP from the current compression stable state to the compression initial state to the UP.

In a specific embodiment, the UP sends a first message indicating that a late access process is completed to the terminal, and then the CP immediately sends a second message to the UP, so that the state of the compression party maintained by the UP is migrated from the current compression stable state to the initial state of the compression party. Therefore, the compression party can enter the compression initial state, namely, the compression party sends the IR message in the IR state, and the previously accessed terminal and the later accessed terminal both receive the IR message, so that all the terminals can successfully decompress the IR message of the compressed data, and a complete context is established according to the decompression result, so that a basis is provided for decompressing the UO-0 message or other messages, and the decompression is accurately performed.

Through the

steps

301 and 302, the late access speed of the terminals in the trunking group can be increased, and the perception of the trunking terminal can be improved.

In the invention, the compression party maintained by the UP is ROHC, and the corresponding decompression party is ROHC of the terminal.

Referring to fig. 5, for the LTE trunking system, the

above steps

301 and 302 are repeated, and after the terminal accesses later, the compression party is triggered to migrate to the compression initial state, so that the terminal accessing later can establish the context of the decompression party, and the decompression succeeds in the first time, thereby avoiding the packet loss phenomenon caused by the decompression failure.

As for the event that the terminal late accesses to the trunking group call detected in step 301, specifically, whether an event that the terminal late accesses to the trunking group call occurs is determined by detecting whether the late access timer is overtime. And when the delayed access timer is overtime, sending a first message for enabling a terminal which enters the cluster group midway to receive the service message so as to complete the delayed access process.

The first message is a traversing Paging message and a Group Call configuration message.

When UP sends out the first message, CP sends the second message to UP immediately, that is, sends the first message to add the terminal to group call service, and after the terminal receives the message, the compression side is transferred from the current stable compression state to the initial compression state by the second message, and in the initial compression state, the compression side sends IR message which can make the decompression side decompress the compressed data directly to the decompression side, and establishes the context providing decompression base.

As for the method of transmitting the second message in step 302, it is transmitted to the compression side by invoking RRM of the CP. The second message is a ROHC compressor state initialization indication message, and in a specific embodiment, the second message may be an RRM _ UP _ PDCP _ INIT _ CSTATE _ IND message. This message is used to inform the UP-maintained compressor ROHC to migrate the state from the current compression stable state to the compression initial state.

For UP of the base station ENB, as shown in fig. 4, the method further comprises the following steps performed thereon:

401. when a late access process of a terminal is completed in cooperation with a CP of the ENB, sending a first message indicating that the late access process is completed to the terminal;

402. and after the first message is sent to the terminal, receiving a second message sent by the CP, and transferring the maintained state of the compression party from the current compression stable state to the compression initial state according to the second message.

Steps

401 and 402 correspond to

steps

301 and 302 performed at the CP of the base station ENB.

Likewise, the first message is a traversing Paging message and a Group Call Config message. The second message is a ROHC compressor state initialization indication message issued by the CP by invoking RRM of the base station ENB. The second message may specifically be an RRM _ UP _ PDCP _ INIT _ CSTATE _ IND message.

The method further comprises performing the following steps at the UP of the base station ENB:

403. when the state of a compression party is transferred from a compression stable state to a compression initial state, switching a UO-0 message of compressed data sent to a terminal accessing the cluster group call into an IR message;

404. when the number of the IR messages continuously sent reaches a preset value, the state of the maintained compression party is transferred to a compression stable state from the current compression initial state;

in the invention, the number of the transmitted IR messages is five, so that all the terminals can receive the IR messages and complete context is established. The predetermined value may be set according to actual conditions, and the present invention is not particularly limited.

405. And when the state of the compression party is transferred from the compression initial state to the compression stable state, switching the IR message of the compressed data sent to the terminal accessing the cluster group call into a UO-0 message.

The method for the terminal to access the group call late provided by the present invention is explained with reference to a specific embodiment provided by fig. 6.

As shown in fig. 6, when the UP-maintained ROHC compressor of the base station ENB starts, in an initial state of compression, five IR messages are sent to the terminal UE1 that has joined the group call, and after successful decompression, a context is established. Then, the compressor enters a compression stable state, and sends a UO-0 message of compressed data to the terminal UE1, and the terminal UE1 decompressor decompresses the data based on the context.

When the terminal UE2 accesses later, the state of the compressing side ROHC maintained by UP of the base station ENB is transferred from the compression stable state to the compression initial state, thus, the compressing side ROHC enters the compression initial state and continuously sends five IR messages, so that the terminal UE1 and the terminal UE2 can successfully decompress and establish a context at the same time; after sending five IR messages, the UE enters a compression stable state, and further sends UO-0 messages to the UE1 and the UE2, and the UE2 can decompress successfully at the first time on the basis of the established context.

Thus, compared with the prior art shown in fig. 2, the process that the terminal UE2 waits for a new period to enter the compression initial state is effectively avoided, and the terminal UE2 listens to the group call service as soon as possible in the late access process by migrating the compression party back to the compression initial state.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A method for a terminal to access a cluster group call late is characterized in that the method comprises the following steps executed in a CP of a base station ENB:

when an event that a terminal accesses to the cluster group calling later is detected, the terminal completes the later access process of the terminal in cooperation with UP of the base station ENB; determining whether an event that a terminal accesses to a cluster group call after delay occurs or not by detecting whether a delay access timer is overtime or not;

after the UP sends a first message indicating that the late access process is completed to the terminal, sending a second message for transferring the state of a compression party maintained by the UP from the current compression stable state to the compression initial state to the UP; wherein, the first message is a traversing Paging message and a Group Call Config message; transmitting the second message by invoking RRM of the base station ENB; the second message is the ROHC compressor state initialization indication message maintained by the UP.

2. A method for a terminal to access cluster group calling later is characterized in that the method comprises the following steps executed at UP of a base station ENB:

when a late access process of a terminal is completed in cooperation with a CP of the ENB, sending a first message indicating that the late access process is completed to the terminal; the first message is a trunk Paging message and a Group Call Config message;

after the first message is sent to the terminal, receiving a second message sent by the CP, and transferring the maintained state of the compression party from the current compression stable state to the compression initial state according to the second message; the second message is a ROHC compressor state initialization indication message maintained by the UP and is sent by the CP by invoking RRM of the base station ENB.

3. The method of claim 2, further comprising performing the following steps at the UP of the base station ENB: