CN100411326C - A method for dynamically sharing channel code resources among different types of channels - Google Patents

Abstract

The invention discloses a method for dynamically sharing code resources between different types of channels. The method first reserves channel codes for various channels that need to share code resources, and then monitors the use of the channel codes of the above-mentioned channels. Evaluate the use of channel codes reserved for various channels according to the monitoring results, and finally use the evaluation results to allocate reassignable channel codes for channels with excess code resources to channels with insufficient code resources. Using the above scheme can optimize the allocation of limited channel code resources among different types of channels in the system, improve the utilization rate of channel codes, increase the number of users that can be accessed by the system, or reduce the call loss rate or make the average transmission of user data The rate is increased, thereby improving the overall performance of the system.

Description

A method for dynamically sharing channel code resources among different types of channels

technical field

The invention relates to a mobile communication system, especially a method for sharing system resources.

Background technique

In a mobile communication system, there are generally multiple channels used to transmit user data, and rational use of these channels is an important means to effectively use system resources. For example, in a wideband code division multiple access (WCDMA) mobile communication system, there are mainly three channels in the downlink direction that can be used to transmit user data, namely a dedicated channel (DCH), a forward access channel (FACH) and a shared channel (DSCH). ). The above-mentioned channels are distinguished by channel codes, that is to say, the channels in the WCDMA system correspond to different channel codes, and the size of the channel code determines the bandwidth of the channel. Allocating a channel with a certain bandwidth to a specific user is actually allocating a channel code of a specific size to the user. Therefore, for the three channels of DCH, FACH and DSCH in the WCDMA system, it is necessary to divide all channel codes into three parts reasonably, which are respectively used for the above-mentioned different types of channels. Since the number of channel codes that can be used simultaneously by each cell in the WCDMA system is limited, it is an urgent need to solve the problem of rationally allocating the limited channel code resources to different types of channels so that the channel code resources can be fully utilized. The problem.

At present, the method for realizing the allocation of channel code resources among different types of channels is static allocation. That is, before the system runs, the available channel codes are divided into three parts according to the estimation and calculation of the channel utilization in advance, corresponding to the dedicated channel DCH, the shared channel DSCH and the common channel including FACH. According to this allocation principle, during the operation of the system, the channel codes between different parts cannot be cross-used, for example, the channel code of DSCH will not be used for DCH or common channel, and the channel code of DCH cannot be used for DSCH or common channel . Assuming that channel codes are allocated according to the proportion shown in Figure 1, except for a small part that is fixedly used for downlink common channels, other channel codes that can be allocated are reserved for dedicated channel DCH and shared channel DSCH according to a certain ratio. Assuming that a new user attempts to access the cell, the system first determines which type of channel the new user uses according to a certain channel type selection strategy.

If it is determined to use DCH, then the system determines how much bandwidth the user needs a DCH according to the user's data rate and other information, and thus determines how much channel code needs to be allocated to the user. Obtained from channel code resources reserved for DCH. When there are many users who have access and use DCH in the cell, most of the channel codes have been allocated, and there may not be enough channel codes to allocate to this new user in the remaining channel code resources reserved for DCH. . At this time, the new user cannot successfully access due to the shortage of code resources. For the user, the communication requirements cannot be met, and for the operator, the profit is reduced because the channel capacity of the system cannot be fully utilized. .

If the system selects a strategy based on the channel type and determines that the new user uses the shared channel DSCH, the system does not need to explicitly allocate a fixed code resource, but dynamically allocates the channel code of the DSCH to the user on the DSCH through the DSCH scheduling algorithm use. On average, since the channel code resources reserved for DSCH are fixed, the more users use DSCH, the less channel code resources are allocated to each user, and the lower the data transmission rate is. When transmitting a certain amount of data The longer it takes, the lower the communication quality perceived by the user.

In an actual application environment, the time when a user requests to access a cell and the number of users who request to access a cell within a period of time are randomly distributed, and the types of services requested by different users when accessing a cell are also unpredictable. That is to say, the request of the user to access the cell and use the DCH or DSCH channel is random in time. Assume that in a certain period of time, many users request to access the cell and most of the users are allocated to DCH channels, so the channel code resources originally reserved for DCH in the cell will be insufficient, resulting in In this case, the probability that the user cannot make a call (called the call loss rate) is particularly high, and the system performance is reduced. If at the same time, the number of users allocated to the DSCH is small, and the amount of data to be transmitted on the DSCH is not large, the channel resources originally reserved for the DSCH are greater than actual needs, resulting in a certain waste of resources. On the contrary, if many users request to access the cell within a certain period of time and are assigned to the DSCH channel, since the channel code reserved for DSCH, that is, the channel bandwidth, is also limited, the channel bandwidth and The number of users on the DSCH channel is inversely proportional. For users, the data transmission rate will be reduced, so that the data to be transmitted cannot be sent out in time, the delay of data transmission will also become very long, and the communication quality will not be guaranteed. At this time, the channel code resources reserved for the DCH in the cell are not allocated because there are not many users using the DCH, and the system capacity is not fully utilized.

From the above, it can be known that the biggest disadvantage of the existing method for statically allocating channel code resources is that it cannot maximize the utilization efficiency of channel code resources, thereby reducing user satisfaction while limiting system capacity, especially call quality. Success rate.

Contents of the invention

The purpose of the present invention is to provide a method for dynamically sharing channel code resources between different types of channels that can improve the utilization rate of channel code resources. Using this method can make the system fully use all channel code resources in the cell, so that the system channel Capacity is fully utilized and communication quality is improved.

In order to achieve the above object, the method for dynamically sharing code resources between different types of channels provided by the present invention includes:

Reserve channel codes for various channels that require shared code resources;

Monitor the use of the channel codes of the above-mentioned channels. For dedicated channels, it can be realized by counting the proportion or absolute number of allocated channel codes among the channel codes reserved for dedicated channels, or by counting the proportion or absolute number of remaining channel codes ;For the shared channel, it is realized by counting the usage ratio of the channel code within a period of time, and the average data transmission rate or the average amount of data to be transmitted of the users of the shared channel;

Compare the monitoring results with the preset threshold, and evaluate the use of channel codes reserved for various channels;

Using the result of the evaluation, the reassignable channel codes of the channels with excess code resources are allocated to the channels with insufficient code resources.

Before allocating the reassignable channel codes of channels with excess code resources to channels with insufficient code resources, it is also necessary to determine whether the utilization rate of reserved channel codes for channels with excess code resources and channels with insufficient code resources is greater than the specified threshold, if greater than , allocate the reassignable channel codes of the channels with excess code resources to the channels with insufficient code resources, otherwise, continue to monitor the use of channel codes of various channels.

Judgment thresholds are respectively set for various channels that require shared code resources, and are respectively used to monitor the use of channel codes of the corresponding channels.

Before using the evaluation results to determine the channels with insufficient code resources and the channels with excess code resources, use the evaluation results to determine whether dynamic adjustment of channel code resources is required, and if necessary, determine the channels with insufficient code resources and code resources. If there are excess channels, otherwise, continue to monitor the use of channel codes of various channels.

After determining the channels with insufficient code resources and the channels with excess code resources, it is necessary to determine which channels can reassign code resources, and determine the number of channel codes that can be reassigned to channels with excess code resources.

The number of channel codes that can be redistributed by the channel with excess code resources is determined according to the following steps: if the channel code resources reserved for the dedicated channel are excessive, the number of redistributed channel codes is [(Cd1+Cd2)/2 -Cd] multiplied by the total number of channel codes reserved for DCH;

If the channel code resources reserved for the shared channel are excessive, the number of redistributed channel codes=[(Cs1+Cs2)/2-Cs] multiplied by the total number of channel codes reserved for the shared channel;

Wherein, Cd1 and Cd2 are respectively the first threshold and the second threshold of the usage of the channel code set for the dedicated channel, and Cd is the current usage of the channel code of the dedicated channel;

Cs1 and Cs2 are respectively the first threshold and the second threshold of the usage of the channel codes set for the shared channel, and Cs is the current usage of the channel codes of the shared channel.

Before allocating the channel codes that can be reassigned from the channels with excess code resources to the channels with insufficient code resources, it is necessary to determine the channel codes that can be used for reassignment.

Channel codes with adjacent positions in the code tree are preferentially selected, and channel codes that are not used in the code tree are preferentially selected for reallocation.

When reserving channel codes for various channels, the historical statistics of the proportion of data services in the system to all services are used to reserve channel codes for each channel.

Since the present invention monitors the use of channel codes used by various channels, and dynamically allocates channel code resources between different channels according to the monitoring results, the limited channel code resources in the system can be optimized between different types of channels. The distribution of channel codes can improve the utilization rate of channel codes, increase the number of users that can be accessed by the system, or reduce the call loss rate or increase the average transmission rate of user data, thereby improving the overall performance of the system.

Description of drawings

FIG. 1 is a schematic diagram of static allocation of channel code resources between different types of channels;

Fig. 2 is the embodiment flowchart of method of the present invention;

FIG. 3 is an example diagram of dynamic allocation of channel codes using the method described in FIG. 2 .

Detailed ways

The essence of the present invention is that on the basis of statically reserved channel codes, the system monitors the use of channel code resources reserved for various channels in the cell at any time. If the system detects that some channel code resources are excessive and some If the channel code resources are insufficient, the system temporarily reallocates part of the code resources of the channels with excess code resources to the channels with insufficient code resources through a certain method, so as to improve the system capacity and communication quality while making full use of the code resources.

The code resource sharing of DCH and DSCH is taken as an example below, and the present invention will be further described in detail in conjunction with the accompanying drawings.

Fig. 2 is a flowchart of an embodiment of the method of the present invention. The embodiment described in FIG. 2 uses a dedicated channel and a shared channel as examples to describe the sharing of channel codes. According to Figure 2, the system monitors the use of channel code resources reserved for DCH and DSCH in the cell at any time. If the system detects that one of the channel code resources is excessive and the other is insufficient, the system uses a certain method to reduce the excess code resources. Part of the code resources of one party is temporarily reallocated to the other party with insufficient code resources. In order to accomplish the above tasks, some threshold values need to be set in advance, which are respectively used to monitor the usage of the channel codes of the corresponding channels, so as to judge whether the utilization of the channel code resources is sufficient or surplus. Specifically, set the first threshold Cd1 and the second threshold Cd2 of the channel code usage for the DCH, set the first threshold Cs1 and the second threshold Cs2 of the channel code usage for the DSCH, and set the user's average rate threshold Rs for the DSCH channel .

Firstly, the channel code initialization operation is performed in step 1, and channel code resources are reserved for DCH and DSCH, that is, a certain proportion of channel codes is reserved for DCH and DSCH. There are many methods for initializing channel code reservation. For example, channel codes are reserved for each channel based on the historical statistical value of the proportion of data services in the system to all services. The following is a simple estimation method, of course, it is not limited to this method in practice: Assume that through historical statistics, there is a certain percentage in the cell, for example, A% of the services are data services and all data services use DSCH, then we can A% of the channel codes available in the cell are reserved for DSCH, and other parts are reserved for DCH. At the same time, considering that the traffic in the cell may be bursty, the channel code reserved for DSCH can be increased by a small percentage on the basis of A%, such as B%. Of course, B% is configurable here. .

Assuming that a new user accesses and uses a channel code in step 2, at this time, the system will determine the channel type and bandwidth that meet the requirements for the newly accessed user based on the reason for the user's access request and the channel type selection algorithm. If it is determined that the user uses DCH, allocate an appropriate number of channel codes to the new user from the code resources reserved for DCH according to the bandwidth required by the user; if DSCH is used, let the newly added user and other users who have been allocated to DSCH The channel code resources of the DSCH are shared together. It should be noted that different channel type selection strategies may allocate different channel types to access users.

If the channel has user access, it is necessary to monitor the channel code usage of various channels in step 3. Due to the difference in the way DCH and DSCH use channel code resources, the monitoring of channel code usage is also divided into two different One part is used to monitor the use of channel codes reserved for DCH, denoted by Cd, and the other is used to monitor the use of channel codes reserved for DSCH, denoted by Cs. For the use of channel codes reserved for DCH, it is only necessary to directly count the proportion or absolute quantity of allocated channel codes among the channel codes reserved for DCH, or count the proportion or absolute quantity of remaining channel codes.

Since the use of the DSCH channel is different from the use of the DCH channel, usually multiple users use the shared channel at the same time. Therefore, for the use of the channel code reserved for the DSCH, the usage ratio of the code resource within a period of time can be calculated. It is realized by monitoring the average data transmission rate of the user on the DSCH or the average amount of data to be transmitted.

After obtaining the monitoring result of the usage of the channel code in step 3, it is necessary to evaluate the usage of the channel code in step 4 according to the monitoring result. There may be multiple specific evaluation methods based on different standards. In this example, for the channel code resources reserved for DCH, if the proportion of channel codes that have been allocated is higher than a preset threshold Cd1 (for example 95%), it can be considered that the channel code resources reserved for DCH have been fully utilized; on the contrary, if the allocated ratio is less than another different threshold Cd2 (for example, 60%), it can be considered that the channel code resources reserved for DCH Resources are left over. For channel code resources reserved for DSCH, if the statistical results show that the usage ratio of channel codes reserved for DSCH is higher than the threshold Cs1 (for example, 90%) within a period of time, and the average rate of users on DSCH is lower than Threshold Rs, it can be considered that the channel code resources originally reserved for DSCH are not enough to meet the needs of data transmission; on the contrary, if the statistical results show that the usage ratio of channel codes reserved for DSCH is lower than the threshold Cs2 within a period of time, then you can It is considered that there are remaining channel code resources reserved for DSCH.

After obtaining the evaluation result of the use of channel codes in step 4, it is necessary to make a dynamic allocation decision on whether to re-allocate channel codes according to the evaluation results in step 5. Then judge the judgment result in step 6, if the judgment result is that dynamic allocation is needed, then perform the following step 7, otherwise it means that dynamic allocation is not required, so return to step 3 to continue monitoring the usage of channel code resources.

In this example, the method used in step 5 to judge whether it is necessary to dynamically allocate channel codes between different types of channels is as follows: If the evaluation result shows that there are remaining channel codes reserved for DCH and DSCH, then DCH is not required Dynamic allocation of channel codes between DCH and DSCH; if there are surplus channel codes reserved for DCH and insufficient channel codes reserved for DSCH, then part of the channel code resources reserved for DCH need to be reallocated to DSCH channels; if If there are surplus channel code resources reserved for DSCH but insufficient channel code resources reserved for DCH, then part of the channel code resources reserved for DSCH needs to be reallocated to DCH channels.

In the judgment operation of the above-mentioned step 6, the following judgments may also be included in practice. It is also necessary to judge whether the utilization rate of the reserved channel codes of the channels with excess code resources and the channels with insufficient code resources is greater than the specified threshold. The reassignable channel codes of the excess channels are allocated to the channels with insufficient code resources, otherwise, the usage of the channel codes of various channels is continuously monitored. The purpose of this judgment is to dynamically allocate channel codes only when there is a large difference in the use of channel codes reserved for the DCH and DSCH channels, so as to avoid too frequent switching between the two channels. The channel code is adjusted, so that the adjustment process occupies too many system resources. Certainly, in order to realize the above-mentioned judgment operation, the threshold also needs to be set in advance.

If after the judgment in step 6, it is determined that the channel codes need to be redistributed between DCH and DSCH, then in step 7, determine the number of channel codes that need to be redistributed. In practice, there may be multiple implementation methods. This example adopts the way is:

If the channel code resources reserved for the DCH are excessive, the number of channel codes to be reallocated is [(Cd1+Cd2)/2-Cd]*the total number of channel codes reserved for the DCH.

If the channel code resources reserved for DSCH are excessive, the number of channel codes to be reallocated is [(Cs1+Cs2)/2-Cs]*the total number of channel codes reserved for DSCH.

After determining the number of channel codes used for redistribution, it is also necessary to determine which channel codes need to be redistributed. Therefore, in step 8, it is necessary to determine which channel codes originally reserved for DCH (or DSCH) are redistributed to DSCH ( or DCH).

Due to the fact that there is such a fact in practice, if the position of the channel code assigned to a channel type is continuous in the code tree, then when using this part of the code resources, the relative position of the channel code in the code tree is discontinuous For the situation, it has higher usage efficiency. Therefore, an optimal method for determining the reassigned channel code is to reassign the code resources with adjacent positions in the code tree to another channel. Right now:

If the channel codes reserved for the DCH are excessive, the part of the channel codes reserved for the DCH and channel code resources reserved for the DSCH that have adjacent positions in the code tree is reallocated to the DSCH. When it is necessary to select a part of the channel codes reserved for DCH and allocate them to DSCH, in order to reduce the reconfiguration process for existing users, the re-allocated channel codes should be selected from the idle channel codes that are not used at that time. And vice versa.

Finally, in step 9, implement the dynamic allocation of channel codes between different channels, that is, use the re-reserved channel code resources for DCH and DSCH respectively according to the results of the previous execution, and record the re-reserved channel code resources and the initial reserved channel code resources. Different parts among the reserved channel code resources. Then turn to step 3, and repeat the monitoring of channel code usage according to the re-reserved channel code, so as to facilitate subsequent channel code redistribution.

FIG. 3 is an example diagram of dynamic allocation of channel codes using the method described in FIG. 2 . Figure 3 shows the usage of channel codes after the system has been running for a period of time, where the shaded part represents the channel codes being used by the user, and the blank part represents the channel code resources not being used.

Between time t0 and t1, the channel codes reserved for the DCH have been completely used by users, but there are still many channel codes reserved for the DSCH. During this period, the new user Ua requests to access the cell and use the DCH, but since there are no remaining channel codes available for the user in the channel codes reserved for the DCH, the access request of the user Ua is rejected by the system. That is, the call of user Ua fails.

At time t1, the system monitors the use of the channel codes, and determines to allocate part of the channel codes reserved for the DSCH to the DCH through evaluation and judgment.

At time t2, the DCH obtains the channel code resource reallocated from the DSCH channel, so there is a certain amount of channel code reserved for the DCH, which can satisfy the access of new users.

At time t3, the new user Ub requests to access the system and use the DCH, because there are remaining channel codes, the user successfully accesses the system. At this time, both DCH and DSCH have only a small amount of remaining channel codes, and channel code resources are fully utilized, thereby improving system capacity at the same time.

The example cited above only illustrates the shared use of channel codes for two channels. When there are more than three channels sharing channel codes, the present invention is also applicable, only in the monitoring of channel usage and the evaluation of various channels according to the monitoring results. Add some judgments when using the channel code. When there are many types of channels that need to share channel codes, the decision relationship will be more complicated. A simplified method is to set judgment thresholds for various channels and monitor the channel code usage of various channels, and then determine the channel type with the most excess channel code resources and the channel code resources that are most scarce according to each monitoring result channel types, and then redistribute channel codes between these two channels. By repeating such a process, a reasonable allocation of channel code resources among different channels can be achieved.

In practice, in order to make the control relationship clear, the sharing of channel codes can also be managed by grouping. For example, there are three channels A, B, and C that need to share the channel code, and AB can be bundled together as a channel, so that the method of the embodiment of the present invention can be used as the first process in Channel code sharing adjustment or redistribution between channel type AB and channel C type; in the above process, another process is nested, that is, the second process, which is dedicated to the adjustment of channel codes between channel types A and B to manage. Assume that according to this management method, when the use of the channel codes of the three channels A, B, and C does not meet the preset adjustment conditions, the channel codes among the above three channels will not be redistributed. If it is judged that the channel codes of the A-type channel are insufficient, and the channel codes of the B-type channel are surplus, and a part can be separated for redistribution, then the second process can be used to directly redistribute the channel A and B. channel code.

If the above-mentioned channel type with remaining channel codes and part of which can be allocated for reallocation is C, then the channel codes that can be allocated for channel C can be transferred from the first process to the second process, and the second process Complete channel code reassignment.

Claims (9)

1. A method for dynamically sharing code resources between dissimilar channels, characterized in that it comprises: Reserve channel codes for various channels that require shared code resources; Monitor the use of the channel codes of the above-mentioned channels. For dedicated channels, it can be realized by counting the proportion or absolute number of allocated channel codes among the channel codes reserved for dedicated channels, or by counting the proportion or absolute number of remaining channel codes ;For the shared channel, it is realized by counting the usage ratio of the channel code within a period of time, and the average data transmission rate or the average amount of data to be transmitted of the users of the shared channel; Comparing the monitoring result with a preset threshold, evaluating the use of channel codes reserved for various channels; Using the result of the evaluation, the reassignable channel codes of the channels with excess code resources are allocated to the channels with insufficient code resources. 2. The method for dynamically sharing code resources between different types of channels according to claim 1, characterized in that: before distributing channel codes that can be redistributed from channels with excess code resources to channels with insufficient code resources, it is also necessary to judge Whether the utilization rate of the reserved channel codes of the channels with excess code resources and channels with insufficient code resources is greater than the specified threshold, if it is greater than the channel codes that can be reassigned from the channels with excess code resources to the channels with insufficient code resources, otherwise, continue to The use of channel codes for various channels is monitored. 3. The method for dynamically sharing code resources between different types of channels according to claim 1, characterized in that: decision thresholds are respectively set for various channels that need shared code resources, and are respectively used for the use of channel codes of corresponding channels The situation is monitored. 4. The method for dynamically sharing code resources between different types of channels according to claim 1, 2 or 3, characterized in that: before using the result of the evaluation to determine the channels with insufficient code resources and the channels with excess code resources, Use the evaluation result to determine whether dynamic adjustment of channel code resources is required, and if necessary, determine channels with insufficient code resources and channels with excess code resources, otherwise, continue to monitor the use of channel codes for various channels. 5. The method for dynamically sharing code resources between different types of channels according to claim 4, characterized in that, after determining the channels with insufficient code resources and the channels with excess code resources, it is also necessary to determine which channels can reassign codes resources, and determine the number of channel codes that can be reallocated to channels with excess code resources. 6. The method for dynamically sharing code resources between different types of channels according to claim 5, wherein the determination of the number of channel codes that can be redistributed to channels with excess code resources is carried out according to the following steps: if reserved for If the channel code resources of the dedicated channel are excessive, the number of redistributed channel codes is [(Cd1+Cd2)/2-Cd] multiplied by the total number of channel codes reserved for DCH; If the channel code resources reserved for the shared channel are excessive, the number of redistributed channel codes=[(Cs1+Cs2)/2-Cs] multiplied by the total number of channel codes reserved for the shared channel; Wherein, Cd1 and Cd2 are respectively the first threshold and the second threshold of the usage of the channel code set for the dedicated channel, and Cd is the current usage of the channel code of the dedicated channel; Cs1 and Cs2 are respectively the first threshold and the second threshold of the usage of the channel codes set for the shared channel, and Cs is the current usage of the channel codes of the shared channel. 7. The method for dynamically sharing code resources between different types of channels according to claim 1, characterized in that, before the channel codes that can be redistributed in channels with excess code resources are assigned to channels with insufficient code resources, it is also necessary to determine A channel code that can be used for reassignment. 8. The method for dynamically sharing code resources between different types of channels according to claim 7, wherein the channel codes with adjacent positions in the code tree are preferentially selected, and channels that are not used in the code tree are preferentially selected code for reassignment. 9. The method for dynamically sharing code resources between different types of channels according to claim 1, wherein the channel codes are reserved for each channel through the historical statistics of the proportion of data services in the system to all services.

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