CN102215236B - Working mode switching method and device of robust header compression protocol (ROHC) layer - Google Patents

Abstract

The invention discloses a working mode switching method and device of an ROHC layer. Wherein, the method includes: when it is necessary to switch the working mode of the ROHC layer, judging whether context information conversion is required according to the working modes before and after switching; if so, setting the context information of the switched working mode according to the context information of the current working mode , and initiate a working mode switch. According to the present invention, the problem of waste of learning resources in the switching of ROHC working modes is solved, and the utilization rate of system resources is improved.

Description

Working mode switching method and device for robust header compression protocol layer

technical field

The present invention relates to the field of communications, in particular to a method and device for switching working modes of a Robust Header Compression Protocol (Robust Header Compression Protocol, ROHC) layer.

Background technique

ROHC is the abbreviation of Robust Header Compression Scheme, which is a general IP-based compression technology, which can be applied to any standard of 3G (3rd Generation Partnership Project, third generation partnership project), and can also be applied to LTE (Long Term Evolution, long-term evolution) and other technologies mainly work between the base station and the user terminal. ROHC mainly compresses the header of the packet flow. Its functional entity is divided into a compression end and a decompression end. The compression end and the decompression end need to maintain a set of context information respectively. When the compression end is sure that the decompression end has maintained sufficient context information, it will enter compression. state, start sending compressed packets. After that, the compressor and the decompressor will selectively update their respective context information according to the current message, so as to ensure the synchronization of the context information of the compressor and decompressor.

ROHC adopts different compression algorithms for the changing rules of each domain value in the data packet header. Among them, the list compression (List compression) algorithm is specially used to compress RTP (Real-time Transport Protocol) CSRC (Contribution Source, providing source, Used to identify sub-signal source) options, the RTP CSRC option is composed of a series of elements (items), called a linked list (list), and the elements (items) in the linked list are each CSRC value, in adjacent packets Between, the linked list rarely changes, if there is no change, the compression end may not send any data. If there is a small change, the compression end only needs to send the changed part of the linked list, so as to achieve the purpose of compression; the table-based element (Table-based item) compression algorithm is used to effectively compress a single element (item ), its basic idea is: the compression end assigns a unique corresponding label (index) to each item, and the compression end saves the sent item and its index to a Table table (also known as the relationship table between elements and labels ), when the compression end is sure that the decompression end already knows the correspondence between index and item, the compression end only needs to send the index instead of the item, so as to achieve the purpose of compression; similarly, the decompression end also maintains a Table table, which represents The received item and the corresponding index are stored in . When the decompression end only receives the index but no item, it can find the corresponding item in the Table table according to the index, so as to decompress correctly. The compression side introduces a mark between each pair of item and index: Known (known bit). Known has two values, 0 and 1. When Known is 0, it means that the compression end has not yet confirmed whether the decompression end knows the correspondence between the item and index; when Known is 1, it means that the compression end is sure that the decompression end has After learning the correspondence between the pair of item and index. Known is initially 0. When to set Known to 1, that is, when the compressor is sure that the decompressor has learned the corresponding relationship, it is related to the specific working mode.

In the prior art, ROHC supports three working modes: unidirectional working mode (ie, U mode), bidirectional optimized working mode (ie, 0 mode), and bidirectional reliable working mode (ie, R mode).

When working in R mode, the context of the compressor and decompressor is synchronized mainly through feedback information. A Table table is maintained for each pair of index and item in the context information of the compression end. The Table table is shown in Table 1, where The SN of SN stores the SN value of the sent packet carrying the relationship between index and item. When any SN in the table is confirmed by the feedback information, the Known is set to 1, and the SN field in the table is cleared.

Table 1

Index Known Item SN1, SN2,...

In U/O mode, due to the lack of feedback, the table maintained by the compression end is shown in Figure 2. The compression end needs to maintain a counter value in the table, which is used to represent the count of the corresponding relationship between the sent index and item. After the count value reaches a certain number of sending times, the Known is set to 1.

Table 2

Index Known Item Counter

A Table table is also maintained in the context of the decompression end. Whenever the decompression end receives a pair of item and index, it puts it into the table and sets the corresponding Known to 1.

At the same time, in order to update the reference linked list in a timely and effective manner, a List library is maintained in the context information of the compressor. This library stores all linked lists that may be used as a reference list. Since the corresponding relationship between item and index has been maintained in the Table table, Therefore, the linked list in the List library only needs to save the index value.

According to the different working modes of ROHC, the selection method of the reference linked list is also different. For example: in R mode, the unique identifier of the linked list in the List library is represented by the SN of the data packet, and all SN values of the data packets sent by the list need to be maintained, so that when the feedback information is received, the SN in the feedback information corresponds to The linked list is selected as the reference linked list; in U/O mode, the unique identifier of the linked list in the List library is represented by the Gen_Id (linked list identifier) value, which is randomly generated at the beginning. If the list does not change, the value remains unchanged. If it changes, the value will be incremented by 1. The context information also needs to maintain the sending times of the current list, which is used to select the linked list corresponding to Index in the Gen_Id value as the reference linked list when the sending times reach the upper limit of the sending list.

A List library is also maintained in the context of the decompression side, which is used to select the reference list according to the list mark sent by the compression side. In the current technology, the decompression end can initiate mode conversion at any time according to the current channel environment, bit error rate, delay size, whether the feedback channel exists, service priority, stream packet size, etc., and in U/O mode In the process of switching between the R mode and the R mode, because the context information of the stored linked list is different, the Table table and List library maintained in the context of the compression end and the decompression end will be cleared. After the mode switching is successful, the Table table will be maintained in the new mode and the List library. This mode switching method fails to inherit the previous learning experience, resulting in a waste of learning resources, which in turn affects the compression efficiency of the linked list after the mode switching.

Aiming at the problem of wasting learning resources in the ROHC working mode switching in the related art, no effective solution has been proposed yet.

Contents of the invention

The main purpose of the present invention is to provide a method and device for switching working modes of the robust header compression protocol layer, so as to at least solve the problem of wasting learning resources in the switching of working modes of ROHC.

According to one aspect of the present invention, a method for switching operating modes of the ROHC layer is provided, including: when the operating modes of the ROHC layer need to be switched, judging whether context information conversion is required according to the operating modes before and after switching; if so, according to The context information of the current working mode sets the context information of the switched working mode, and initiates working mode switching.

Among them, judging whether context information conversion is required according to the working modes before and after switching includes: if the current working mode is a one-way working mode or a two-way optimized working mode, when switching to a two-way reliable working mode, it is determined that context information conversion is required; or, If the current working mode is a two-way reliable working mode, when switching to a one-way working mode or a two-way optimized working mode, it is determined that context information conversion is required.

Wherein, setting the context information of the switched working mode according to the context information of the current working mode includes: setting the context information in the second element and label relationship table according to the context information in the first element and label relationship table, wherein the first element The relationship table with tags is the element-label relationship table learned in the current working mode, and the second element-label relationship table is the element-label relationship table corresponding to the switched working mode; according to the context information in the first link library, set the second Context information in two link libraries, wherein the first link library is the link library learned in the current working mode, and the second link library is the link library corresponding to the switched working mode.

The above-mentioned current working mode is a one-way working mode or a two-way optimized working mode. When the switched working mode is a two-way reliable working mode, set the context in the second element-label relationship table according to the context information in the first element-label relationship table The information includes: searching in the first element-label relationship table for an element whose sending count value reaches the first set upper limit, and setting the known bit corresponding to the found element in the second element-label relationship table as a confirmed identification; Setting the context information in the second link library according to the context information in the first link library includes: searching in the first link library for links whose link sending count value reaches the second set upper limit, and linking the found links The road is set as a reference link in the second link library.

When the current working mode is a two-way reliable working mode, and the switched working mode is a one-way working mode or a two-way optimized working mode, the above-mentioned context information in the second element-label relationship table is set according to the context information in the first element-label relationship table The information includes: counting the number of data packet serial numbers SN corresponding to each element in the first element and the label relationship table; taking the counted number as the sending count value of the corresponding element in the second element and the label relationship table, and In the two-element and label relationship table, the known bit corresponding to the element whose sending count value reaches the first set upper limit is set as a determined identifier; the above-mentioned context in the second link library is set according to the context information in the first link library The information includes: counting the number of data packet sequence numbers SN corresponding to each link in the first link library; using the counted number as the sending count value of the corresponding link in the second link library, and sending the count value up to The link with the second upper limit is used as the reference link.

After the working mode switch is initiated, the above method further includes: compressing or decompressing elements according to the context information of the switched working mode.

According to another aspect of the present invention, a device for switching working modes of the ROHC layer is provided, including: an information conversion judging module, which is used to judge whether context switching is required according to the working modes before and after switching when the working mode switching of the ROHC layer is required. Information conversion; an information setting module, used to set the context information of the switched working mode according to the context information of the current working mode when the judgment result of the information conversion judging module is yes; a mode switching module, used to initiate the working mode switching.

Wherein, the information conversion judging module includes: a first determination unit, which is used to determine the need for context information conversion when the current working mode is a one-way working mode or a two-way optimized working mode, and it is desired to switch to a two-way reliable working mode; or, the second The determining unit is configured to determine that context information conversion is required when the current working mode is the bidirectional reliable working mode and it is desired to switch to the unidirectional working mode or the bidirectional optimized working mode.

The above information setting module includes: a relationship table setting unit, which is used to set the context information in the second element and label relationship table according to the context information in the first element and label relationship table, wherein the first element and label relationship table is the current working The element and label relationship table learned in the mode, the second element and label relationship table is the element and label relationship table corresponding to the switched working mode; the link library setting unit is used to set the link library according to the context information in the first link library The context information in the second link library, wherein the first link library is the link library learned in the current working mode, and the second link library is the link library corresponding to the switched working mode.

Wherein, the above-mentioned relationship table setting unit includes: an element search subunit, which is used for the current working mode to be a one-way working mode or a two-way optimization working mode, and when the switched working mode is a two-way reliable working mode, in the first element and label relationship table In the search element, send the element whose count value reaches the first set upper limit; the first relationship table setting subunit is used to set the known bit corresponding to the element found by the element search subunit in the second element and label relationship table as already Determine the identification; the above-mentioned link library setting unit includes: a link search subunit, which is used for the current working mode to be a one-way working mode or a two-way optimized working mode, and when the switched working mode is a bidirectional reliable working mode, in the first link Find links in the library whose count value reaches the second set upper limit; the first link library setting subunit is used to set the link found by the link search subunit as a reference link in the second link library.

Wherein, the above-mentioned relationship table setting unit includes: an element statistics subunit, which is used to count the relationship table between the first element and the label when the current working mode is a two-way reliable working mode, and the switched working mode is a one-way working mode or a two-way optimized working mode The number of the data packet sequence number SN corresponding to each element in the above; the second relationship table sets the subunit, which is used to use the number counted by the element statistics subunit as the sending count value of the corresponding element in the second element and the label relationship table, And in the second element and label relationship table, the known bit corresponding to the element whose sending count value reaches the first set upper limit is set as a determined identification; the above-mentioned link library setting unit includes: a link statistics subunit, used for the current The working mode is a two-way reliable working mode. When the switched working mode is a one-way working mode or a two-way optimized working mode, count the number of data packet sequence numbers SN corresponding to each link in the first link library; The link library setting subunit is used to use the number counted by the link statistics subunit as the sending count value of the corresponding link in the second link library, and use the link whose sending count value reaches the second set upper limit as the reference link .

Through the present invention, the element context information learned before the switch is used to set the element context information after the switch, so that it is not necessary to clear the previous element context information after the switch and re-learn, and the waste of learning resources in the ROHC working mode switch is solved. , improving the utilization of system resources.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

FIG. 1 is a flowchart of a method for switching operating modes of an ROHC layer according to Embodiment 1 of the present invention;

FIG. 2 is a structural block diagram of an apparatus for switching working modes of an ROHC layer according to Embodiment 2 of the present invention.

detailed description

Hereinafter, the present invention will be described in detail with reference to the drawings and examples. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

The embodiment of the present invention considers that when using ROHC to compress the header of the packet flow, the compression end and the decompression end will switch the working mode in some cases, for example, switch from U or O mode to R mode; The learning efficiency of the context information and the effective use of the learning experience before the switching of the working mode provide a method and device for switching the working mode of the ROHC layer.

Example 1

This embodiment provides a working mode switching method of the ROHC layer, which is applicable to the compression end and the decompression end. Referring to FIG. 1, the method includes the following steps (step S102-step S106):

Step S102, when it is necessary to switch the working mode of the ROHC layer, judge whether context information conversion is required according to the working modes before and after switching;

For example, if the current working mode is a one-way working mode (U mode) or a two-way optimized working mode (O mode) (it can also be simplified as "U/O mode"), when you want to switch to a two-way reliable working mode (R mode) , it is determined that context information conversion is required; or, if the current working mode is the R-mode bidirectional reliable working mode, when switching to a unidirectional working mode or a bidirectional optimized working mode, it is determined that context information conversion is required.

Step S104, if yes, setting the context information of the switched working mode according to the context information of the current working mode;

The context information in this embodiment refers to the context information of an element (item), and the context information is usually stored in an element-label relationship table (that is, a Table table) and a link library (List library), and an element-label relationship table and a link library The specific content included in the road library is the same as that in related technologies. For example, in the R mode, the Table table is shown in the previous Table 1; in the U/O mode, the Table table is shown in the previous Table 2. Based on this, setting the context information of the switched working mode according to the context information of the current working mode includes:

1) Set the context information in the second element and label relationship table according to the context information in the first element and label relationship table, wherein, the first element and label relationship table is the element and label relationship table learned in the current working mode, the first The two-element-label relationship table is the element-label relationship table corresponding to the switched working mode;

2) Set the context information in the second link library according to the context information in the first link library, wherein the first link library is the link library learned in the current working mode, and the second link library is the switched The link library corresponding to the working mode.

For the case where the current working mode is a one-way working mode or a two-way optimized working mode, and the switched working mode is a two-way reliable working mode, the above-mentioned context information in the first element-label relationship table is set in the second element-label relationship table. The context information includes: search the first element-label relationship table for an element whose sending count value reaches the first set upper limit, and set the known bit corresponding to the found element in the second element-label relationship table as determined logo;

In this case, the above-mentioned setting of the context information in the second link library according to the context information in the first link library includes: searching for links in the first link library whose link sending count value reaches the second set upper limit, Set the found link as a reference link in the second link library.

For the case where the current working mode is a two-way reliable working mode, and the switched working mode is a one-way working mode or a two-way optimized working mode, the above-mentioned context information in the first element-label relationship table is set in the second element-label relationship table. The context information includes: counting the number of data packet sequence numbers SN corresponding to each element in the first element and the label relationship table; using the counted number as the sending count value of the corresponding element in the second element and the label relationship table, and In the second element and label relationship table, the known bit corresponding to the element whose sending count value reaches the first set upper limit is set as a determined flag;

In this case, setting the context information in the second link library according to the context information in the first link library includes: counting the number of data packet sequence numbers SN corresponding to each link in the first link library; The counted number is used as the sending count value of the corresponding link in the second link library, and the link whose sending count value reaches the second set upper limit is used as the reference link.

In the above conversion process, the linked list identifier Gen_id and the data packet serial number identifier SN can directly assign values to each other.

Of course, for situations where context information conversion is not required according to the working mode before and after switching, for example, switching between U mode and O mode; in this case, after the working mode is switched, the context information before switching can be directly used for compression with unzip.

Step S106, initiating a working mode switch.

Wherein, step S106 may also be executed first, that is, the context information is switched after the working mode is switched.

After the working mode switch is initiated, the above method further includes: compressing or decompressing elements according to the context information of the switched working mode.

In this embodiment, by making full use of the element context information learned before switching to set the element context information after switching, it is not necessary to clear the previous element context information and re-learn after switching, which solves the problem of waste of learning resources in the switching of ROHC working modes , improving the utilization of system resources. At the same time, when using the inherited element context for compression/decompression, the compression efficiency and compression degree can be improved.

The implementation of the above method mainly considers that the Table table maintained by the compressor and the decompressor in U/O mode and R mode are consistent with the actual data of the List library, that is, the actual maintained item values are consistent. For U/O mode and R mode Context differences, transformed as follows:

First of all, Gen_Id and SN can uniquely identify a data packet in U/O mode and R mode, so when U/O mode and R mode are switched to each other, the values of Gen_Id and SN can be converted at the same time.

Among them, Gen_Id is randomly generated for the first time. For the next data packet, the value of Gen_Id will be selectively increased by 1 according to whether the data packet changes or not. At the same time, Gen_Id is used to identify this data packet; A field that uniquely identifies a data packet; since both Gen_Id and SN can uniquely identify a data packet, it is sufficient to assign the two fields to each other during the mode conversion process.

Secondly, when switching from U/O mode to R mode, select the list in the List library that reaches the upper limit of list transmission as a reference list. When switching from R mode to U/O mode, all list tables in the List library The corresponding number of SNs is converted into the number of times the list is sent in U/O mode, and then the list that reaches the upper limit of list sending is selected as the reference list.

Finally, for all mode switching processes, the corresponding relationship between index and item remains unchanged. When switching from U/O mode to R mode, the item in the Table table that reaches the upper limit of item sending is set as a known bit (that is, setting The corresponding Kown is set to ), when switching from R mode to U/O mode, convert the number of SNs corresponding to all items in the Table table into the number of times the item is sent in U/O mode, and then reach the upper limit of item sending item is set to a known bit.

Because the linked list context information maintained in the U mode and the O mode are consistent, when the U mode and the O mode are switched to each other, there is no need to clear the linked list context information, nor to convert the context information in the above-mentioned manner.

The following takes switching from R mode to U mode as an example to illustrate the processing method during the working mode switching process:

The current mode is R mode, the switching mode is U mode, the SN of the current reference list is 21, the actual list value is (3500, 3600, 3601), and the corresponding index is (0, 2, 3), assuming that after the mode is switched The SN of the list to be sent is 24, and its actual list value is (3500, 3600, 3601, 3602). The Talbe table in R mode of the compressor and decompressor is shown in Table 3, and the List library is shown in Table 4.

table 3

Table 4

SN Index1, Index2,  … SN1, SN2,  … 18 0, 1, 2, 3 18 19 0, 1, 3 19 20 0,2 20 twenty one 0, 2, 3 21, 22, 23  …  …  …

After the mode switching, if the Talbe table and the List library and the corresponding context information are cleared, all the list information of the data packets with SN=24 to be sent need to be sent to the decompression terminal, that is, the actual list (3500, 3600, 3601, 3602) The original value is sent, and then the compression end and the decompression end re-synchronize the context information, and maintain the Talbe table and the List library. If the above-mentioned working mode switching method provided by the present embodiment is adopted, the above-mentioned Talbe table and List storehouse are not emptied, but are converted. The converted Talbe table is as shown in Table 5, and the converted List storehouse is as shown in Table 6. Show.

table 5

Indexi (label i) Known (known bit) Item (element) Counter (element count value) 0 1 3500 4 1 1 3501 2 2 1 3600 4 3 1 3601 4  …  …  …  …

Table 6

Gen_id Index1, Index2,  … Counter (link count value) 18 0, 1, 2, 3 1 19 0, 1, 3 1 20 0,2 1 twenty one 0, 2, 3 3  …  …  …

After mode switching, the compressor and decompressor still save the Talbe table and List library after conversion, and the corresponding context information. At this time, the list information of the packet to be sent with SN=24 can be compressed and sent, because the current reference list is ( 3500, 3600, 3601), and the list to be sent is (3500, 3600, 3601, 3602). According to the principle of linked list compression, only the difference between the current list and the reference list needs to be sent, that is, only (3602) needs to be sent to the decompression terminal. Can.

According to the above method provided by this embodiment, it can be ensured that during various mode switching processes, the linked list context information maintained by the compression end and the decompression end will not be cleared, but will be effectively inherited through conversion, thereby ensuring the link list under compression. Seamless mode switching effectively improves the efficiency of linked list compression after mode switching.

Example 2

This embodiment provides a working mode switching device of the ROHC layer, which device can be set on the physical device at the compression end or decompression end, see Figure 2, the device includes:

The information conversion judging module 22 is used for judging whether context information conversion is required according to the working modes before and after switching when it is necessary to switch the working mode of the ROHC layer;

The information setting module 24 is connected with the information conversion judgment module 22, and is used for setting the context information of the switched working mode according to the context information of the current working mode when the judgment result of the information conversion judgment module 22 is yes;

The mode switching module 26 is connected with the information setting module 24 and is used for initiating the working mode switching.

Wherein, the information conversion judging module 22 includes: a first determining unit, used to determine that context information conversion is required when switching to a bidirectional reliable working mode if the current working mode is a one-way working mode or a two-way optimized working mode; or, the second The second determination unit is used to determine the need to perform context information conversion when the current working mode is the bidirectional reliable working mode and it is desired to switch to the unidirectional working mode or the bidirectional optimized working mode.

The above information setting module 24 includes: a relationship table setting unit, which is used to set the context information in the second element and label relationship table according to the context information in the first element and label relationship table, wherein the first element and label relationship table is the current The element and label relationship table learned in the working mode, the second element and label relationship table is the element and label relationship table corresponding to the switched working mode; the link library setting unit is used for according to the context information in the first link library The context information in the second link library is set, wherein the first link library is the link library learned in the current working mode, and the second link library is the link library corresponding to the switched working mode.

According to the different working modes before and after switching, the above-mentioned relationship table setting unit and link library setting unit can be implemented in two ways. The first way is for the current working mode to be a one-way working mode or a two-way optimized working mode, and the working mode after switching is two-way In the case of the reliable working mode, the second method is for the case where the current working mode is the bidirectional reliable working mode, and the switched working mode is the unidirectional working mode or the bidirectional optimized working mode.

method one:

The above-mentioned relationship table setting unit includes: an element search subunit, which is used to search in the first element and label relationship table when the current working mode is a one-way working mode or a two-way optimization working mode, and the switched working mode is a two-way reliable working mode. The element whose count value reaches the first set upper limit is sent by the element; the first relationship table setting subunit is used to set the known bit corresponding to the element found by the element search subunit in the second element and tag relationship table as a determined identifier ;

The above-mentioned link library setting unit includes: a link search subunit, which is used to search in the first link library when the current working mode is a one-way working mode or a two-way optimized working mode, and the switched working mode is a two-way reliable working mode. The link whose count value reaches the second set upper limit is sent by the link; the first link library setting subunit is configured to set the link found by the link search subunit as a reference link in the second link library.

Method 2:

The above-mentioned relationship table setting unit includes: an element statistics subunit, which is used for counting each item in the first element and label relationship table when the current working mode is a two-way reliable working mode, and when the switched working mode is a one-way working mode or a two-way optimizing working mode. The number of the packet sequence number SN corresponding to the element; the second relationship table sets the subunit, which is used to send the count value of the corresponding element in the second element and the label relationship table as the number of the element statistics subunit statistics, and in In the second element and label relationship table, the known bit corresponding to the element whose sending count value reaches the first set upper limit is set as a determined flag;

The above-mentioned link library setting unit includes: a link statistics subunit, which is used for counting each link in the first link library when the current working mode is a two-way reliable working mode, and when the switched working mode is a one-way working mode or a two-way optimized working mode. The number of the packet sequence number SN corresponding to each link; the second link storehouse is provided with a subunit, which is used to use the number counted by the link statistics subunit as the sending count value of the corresponding link in the second link storehouse, A link whose sending count value reaches the second set upper limit is used as a reference link.

In the above conversion process, the linked list identifier Gen_id and the data packet serial number identifier SN can directly assign values to each other.

In order to realize the compression and decompression function, the above device may further include: a compression and decompression module, configured to perform element compression or decompression according to the context information of the switched working mode after initiating the working mode switching.

In this embodiment, by making full use of the element context information learned before switching to set the element context information after switching, it is not necessary to clear the previous element context information and re-learn after switching, which solves the problem of waste of learning resources in the switching of ROHC working modes , improving the utilization of system resources. At the same time, when using the inherited element context for compression/decompression, the compression efficiency and compression degree can be improved.

It can be seen from the above description that the above embodiments can ensure that the context information of the linked list maintained by the compression end and the decompression end is not cleared during various mode switching processes, but is effectively inherited through conversion, thereby ensuring that the linked list Seamless mode switching under compression effectively improves the efficiency of linked list compression after mode switching.

Obviously, those skilled in the art should understand that each module or each step of the above-mentioned present invention can be realized by a general-purpose computing device, and they can be concentrated on a single computing device, or distributed in a network formed by multiple computing devices Alternatively, they may be implemented in program code executable by a computing device so that they may be stored in a storage device to be executed by a computing device, and in some cases in an order different from that shown here The steps shown or described are carried out, or they are separately fabricated into individual integrated circuit modules, or multiple modules or steps among them are fabricated into a single integrated circuit module for implementation. As such, the present invention is not limited to any specific combination of hardware and software.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. A method for switching the working mode of a robust header compression protocol (ROHC) layer is characterized by comprising the following steps:

when the working mode of the ROHC layer needs to be switched, judging whether context information conversion is needed according to the working modes before and after switching;

if so, setting context information of the switched working mode according to the context information of the current working mode, and initiating the switching of the working mode;

wherein the setting of context information of the switched operating mode according to the context information of the current operating mode includes: setting context information in a second element and label relation table according to the context information in the first element and label relation table, wherein the first element and label relation table is an element and label relation table learned in the current working mode, and the second element and label relation table is an element and label relation table corresponding to the switched working mode; and setting context information in a second link library according to the context information in the first link library, wherein the first link library is a link library learned in the current working mode, and the second link library is a link library corresponding to the switched working mode.

2. The method of claim 1, wherein the determining whether context information conversion is required according to the working modes before and after switching comprises:

if the current working mode is a unidirectional working mode or a bidirectional optimization working mode, determining that context information conversion is needed when switching to a bidirectional reliable working mode; or,

and if the current working mode is a bidirectional reliable working mode, determining that context information conversion is needed when the current working mode is to be switched to a unidirectional working mode or a bidirectional optimized working mode.

3. The method according to claim 1, wherein the current operation mode is a unidirectional operation mode or a bidirectional optimized operation mode, and when the switched operation mode is a bidirectional reliable operation mode,

the setting the context information in the second element and tag relation table according to the context information in the first element and tag relation table includes: searching an element with a count value reaching a first set upper limit in the first element and label relation table, and setting a known bit corresponding to the searched element as a determined identifier in a second element and label relation table;

the setting the context information in the second link library according to the context information in the first link library comprises: and searching a link with a link sending count value reaching a second set upper limit in the first link library, and setting the searched link as a reference link in a second link library.

4. The method according to claim 1, wherein when the current operation mode is a bidirectional reliable operation mode, and the switched operation mode is a unidirectional operation mode or a bidirectional optimized operation mode,

the setting the context information in the second element and tag relation table according to the context information in the first element and tag relation table includes: counting the number of the data packet sequence numbers SN corresponding to each element in the first element and label relation table; taking the counted number as a sending count value of a corresponding element in the second element and label relation table, and setting a known bit corresponding to an element of which the sending count value reaches a first set upper limit in the second element and label relation table as a determined identifier;

the setting the context information in the second link library according to the context information in the first link library comprises: counting the number of the data packet serial numbers SN corresponding to each link in the first link library; and taking the counted number as a sending count value of a corresponding link in the second link library, and taking the link of which the sending count value reaches a second set upper limit as a reference link.

5. The method according to any of claims 1-4, wherein after the initiating the operating mode switch, the method further comprises:

and compressing or decompressing elements according to the context information of the switched working mode.

6. An operation mode switching device of a robust header compression protocol ROHC layer, comprising:

the information conversion judging module is used for judging whether context information conversion is needed according to the working modes before and after switching when the working modes of the ROHC layer need to be switched;

the information setting module is used for setting context information of the switched working mode according to the context information of the current working mode when the judgment result of the information conversion judgment module is yes;

the mode switching module is used for initiating the switching of the working modes;

wherein, the information setting module comprises: the relation table setting unit is used for setting context information in a second element and label relation table according to the context information in the first element and label relation table, wherein the first element and label relation table is an element and label relation table learned in the current working mode, and the second element and label relation table is an element and label relation table corresponding to the switched working mode;

and the link library setting unit is used for setting the context information in the second link library according to the context information in the first link library, wherein the first link library is a link library learned in the current working mode, and the second link library is a link library corresponding to the switched working mode.

7. The apparatus of claim 6, wherein the information conversion determining module comprises:

the first determining unit is used for determining that context information conversion is needed when the current working mode is a one-way working mode or a two-way optimization working mode and is to be switched to a two-way reliable working mode; or,

and the second determining unit is used for determining that context information conversion is required to be carried out when the current working mode is a bidirectional reliable working mode and is to be switched to a unidirectional working mode or a bidirectional optimized working mode.

8. The apparatus of claim 6,

the relationship table setting unit includes:

the element searching subunit is used for searching an element with a count value reaching a first set upper limit in the first element and label relation table when the current working mode is a unidirectional working mode or a bidirectional optimization working mode and the switched working mode is a bidirectional reliable working mode;

the first relation table setting subunit is configured to set, in the second element and tag relation table, the known bit corresponding to the element found by the element finding subunit as the determined identifier;

the link library setting unit includes:

the link searching subunit is used for searching a link, the transmission count value of which reaches a second set upper limit, in the first link library when the current working mode is a unidirectional working mode or a bidirectional optimized working mode and the switched working mode is a bidirectional reliable working mode;

and the first link library setting subunit is used for setting the link searched by the link searching subunit as a reference link in a second link library.

9. The apparatus of claim 6,

the relationship table setting unit includes:

the element counting subunit is used for counting the number of the data packet sequence numbers SN corresponding to each element in the first element and label relation table when the current working mode is a bidirectional reliable working mode and the switched working mode is a unidirectional working mode or a bidirectional optimized working mode;

a second relation table setting subunit, configured to use the number counted by the element counting subunit as a sending count value of a corresponding element in the second element-to-tag relation table, and set a known bit corresponding to an element whose sending count value reaches a first set upper limit in the second element-to-tag relation table as a determined identifier;

the link library setting unit includes:

the link counting subunit is used for counting the number of the data packet serial numbers SN corresponding to each link in the first link library when the current working mode is a bidirectional reliable working mode and the switched working mode is a unidirectional working mode or a bidirectional optimized working mode;

and the second link library setting subunit is configured to use the number counted by the link counting subunit as a sending count value of a corresponding link in the second link library, and use a link whose sending count value reaches a second set upper limit as a reference link.