WO2010108406A1

WO2010108406A1 - Random access processing method and processing system

Info

Publication number: WO2010108406A1
Application number: PCT/CN2010/070885
Authority: WO
Inventors: 王喆
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-03-27
Filing date: 2010-03-05
Publication date: 2010-09-30
Also published as: CN101848495B; CN101848495A

Abstract

A random access processing method and processing system are provided in the present invention. During the timing period of an access detection timer corresponding to a random access message, the times of a buffering counter for the random access message in a random access message buffering queue is acquired; and according to a comparison result, the random access message is processed. In the present invention, after the accumulation of the buffering counter for the received same Random Access Channel (RACH) message reaches an access decision threshold value during said period of the access detection timer, a channel request message is reported to a Base Station Controller (BSC), so that the effective utilization ratio of communication resources is increased, and the influence of a phantom random access pulse on the Base Transmitter Station (BTS) performance, such as the drop call rate of a signaling channel as well as the success ratio of random access, is reduced.

Description

Random access processing method and processing system

The present invention relates to the field of mobile communications, and in particular, to a random access processing method and processing system. Background technique

In Global System for Mobile Communication (GSM), random access success rate is an important performance indicator for the performance of wireless communication networks. Due to the random access failure introduced by the broadcast control channel/base station identification code (BSIC, BCCH/Base Station Identification Code), and the excessive traffic, etc., it is possible to modify the configuration and add the carrier frequency. Such as optimization methods to solve. However, the Phantom Random Access Channel (Phantom Random Access Channel) problem has always been an "inevitable" phenomenon, and it has been acquiesced by the industry.

The base transceiver station (BTS, Base Transmitter Station) monitors the wireless signal in the air in real time. When the signal level is higher than the receiving sensitivity, it demodulates it, so the demodulated signal may include some noise. When the traffic of the cell is low, most of the signals demodulated by the BTS are noise, and because of the limited information bits and check bits of the random access channel (RACH, Random Access Channel) pulse, some bits in the noise. It is possible for the pattern to match the valid check sequence of the true RACH pulse, introducing a pseudo-random access problem.

According to the GSM specification 05.05 (page 25), in the absence of traffic, 0.02% of the access noise is erroneously demodulated into access pulses, which means that a pseudorandom access pulse appears every 23 seconds on average. . As the traffic increases, the noise is covered by the real access pulse, and the probability of random access to the noise decreases. However, when the traffic is not very high, an average of up to 120 pseudo-random access pulses occur every hour. FIG. 1 is a random access pulse in a prior art communication system Schematic diagram of the processing flow, as shown in FIG. 1, after the base station decodes the random access pulse (step 1), encapsulates the RACH message (step 2), and then reports the BSC channel request message, and the BSC decision channel allocation proceeds to the subsequent process (step 3). ). That is, according to the wireless subsystem management protocol, after receiving the RACH message, the BTS will send a channel resource request to the base station controller (BSC, Base Station Controller), and then the channel is allocated by the BSC. Obviously, such a frequent pseudo-random access pulse will waste a lot of communication resources, increase the signaling channel drop rate, reduce the random access success rate, and affect the BTS performance.

In the prior art, a random access method is proposed to achieve flexible allocation of access channel media resources, improve access capacity of important services, reduce occupation of network capacity, and improve access efficiency. However, the prior art random access method divides the access channel into multiple sub-category access channels; the sub-category access channel corresponds to a sub-category, and the sub-category is based on one or more attributes, hereinafter referred to as sub-category attributes. To divide, only the service is allowed to access on the sub-category access channel corresponding to its associated sub-category; media resources are allocated for each sub-category access channel respectively; subsequently, the user terminal acquires the sub-category associated with the service to be accessed Corresponding sub-category access channel and media resource information allocated thereto, determining whether the to-be-accessed service is allowed to access, and if possible, attempting to access. The prior art only proposes a rule for dividing an access channel into a plurality of sub-category access channels. Summary of the invention

The technical problem to be solved by the present invention is to provide a random access processing method and a processing system, which can save communication resources, reduce the signaling channel drop rate, and improve the random access success rate.

In order to solve the above technical problem, the present invention provides a random access processing method, which includes the following steps:

Obtaining, according to a timing period of the access detection timer corresponding to the random access message, a number of times of the buffer counter of the random access message in the random access message buffer queue;

Comparing the number of times the buffer counter of the random access message is compared with a preset access decision threshold And; according to the comparison result, the random access message is processed.

When the comparison result is the number of times of the buffer counter of the random access message in the random access message buffer queue, when the access determination threshold is reached, the processing of the random access message includes:

And reporting a base station controller channel request message, and deleting an element corresponding to the random access message from the random access message buffer queue.

When the comparison result is that the number of the buffer counters of the random access message in the random access message buffer queue is not up to the access determination threshold, the processing of the random access message includes:

And deleting an element corresponding to the random access message from the random access message buffer queue. The method also includes:

Determining that the random access message buffer queue receives the random access message for the first time, adding an element corresponding to the first received random access message to the random access message buffer queue, and starting An access detection timer corresponding to the random access message.

The number of times of the buffering counter of the random access message in the random access message buffering queue is: receiving a random access message again during the timing period of the access detecting timer, and the random access message is The count of the cache counter is incremented by one.

The element corresponding to the deletion random access message includes: the random access message, a buffer counter with an initial value of 1 of the random access message, a sequence number of an access detection timer corresponding to the random access message, and The access determination threshold.

The access decision threshold is set according to the traffic volume size.

The timing period of the access detection timer is controlled by the number of transmission distribution slots, the access determination threshold, and the maximum number of retransmissions, and channel combination parameters determined according to the number of transmission distribution slots and the configuration of the common control channel. .

The present invention also provides a random access processing system, including at least: The random access message buffer queue maintenance update module is configured to cache an element corresponding to the random access message, and obtain the random in the random access message cache queue in a timing period of the access detection timer corresponding to the random access message The number of times the cache counter of the access message is compared; the number of times of the buffer counter of the random access message is compared with a preset access decision threshold; and according to the comparison result, the reporting of the base station controller channel request message is performed and from the random The element corresponding to the random access message is deleted from the access message buffer queue; or the element corresponding to the random access message is directly deleted from the random access message buffer queue.

The system also includes:

a random access message control parameter maintenance module, configured to start the access detection timer corresponding to the random access message, where the initial value of the random access message is 1 for the cache counter, the random access The sequence number of the access detection timer corresponding to the message and the traffic volume level according to the access determination threshold.

Therefore, the random access processing method and system of the present invention improves the communication by reporting the BSC channel request message after the buffer counter of the same RACH message is accumulated in the period of the access detection timer to reach the access determination threshold. The effective utilization of resources reduces the impact of pseudo-random access pulses on BTS performance such as signaling channel drop rate and random access success rate. DRAWINGS

1 is a schematic diagram of a random access pulse processing flow in a prior art communication system;

2 is a flowchart of a random access processing method according to the present invention;

3 is a flowchart of an embodiment of a random access processing method according to the present invention;

FIG. 4 is a schematic structural diagram of a random access processing system according to the present invention. detailed description

2 is a schematic diagram of a random access pulse processing flow in a communication system according to the present invention. As shown in FIG. 2, the existing base station decodes the random access pulse, reports the RACH message (step 11), and reports the BSC. The channel request message, the BSC decision channel allocation is entered between the subsequent processes (step 13), and a random access processing procedure is added (step 12).

The present invention adds a random access processing procedure, that is, step 12, before the forwarding of the BSC channel request message by the prior art frame control unit. The step 12 includes: analyzing the RACH message reported by the existing channel processing unit, and determining to receive in the timing period. If the number of identical RACH messages reaches the value of the preset access decision threshold, the channel is allowed to be allocated to the RACH message, thereby achieving a non-conforming condition (ie, a value that does not reach the access decision threshold within the period). Filtering of RACH messages.

FIG. 3 is a flowchart of an embodiment of a random access processing method according to the present invention. As shown in Figure 3, the following process is included:

First, the random access (RACH) message buffer queue is initialized, that is, when the RACH message is received for the first time, the element corresponding to the RACH message needs to be added in the RACH message buffer queue, and an access detection is initiated for the RACH message. Timer. Then, the same RACH message is sent to the reporting condition, and the process is specifically as shown in FIG. 3:

Step 100: Receive a RACH message.

Step 101: Determine whether the RACH message is included in the RACH message buffer queue, that is, determine whether the RACH message is received for the first time. If it is determined that the RACH message buffer queue is the first time to receive the RACH message, perform step 102: if not The RACH message is received for the first time (ie, the received RACH message has been included in the RACH message buffer queue, that is, the operation of step 102 has been performed, and the RACH message is the same RACH message received again), then Go to step 103.

Step 102: Add an element corresponding to the received RACH message to the RACH message buffer queue, and start an access detection timer corresponding to the RACH message, to process the RACH message in a timing period, and continue to step 103.

Steps 100 to 102 are the process of initializing the RACH message buffer queue, and receiving This initialization is required for different RACH messages. The elements added in the RACH message buffer pair column include: a RACH message, a buffer counter with an initial value of 1 for the RACH message, a sequence number of the access detection timer corresponding to the RACH, and an access decision threshold. then,

Step 103: Determine, in the timing period of the access detection timer corresponding to the RACH message, whether the number of times of the buffer counter of the RACH message in the RACH message buffer queue has reached the value of the access determination threshold. If yes, go to step 104. The base station controller channel request message is reported, and the element corresponding to the RACH message is deleted from the RACH message buffer queue; if not, step 105 is performed: returning to wait for the RACH message to be received again in the timing period, and then performing step 100.

The processing when the RACH message is received within the timing period of the access detection timer is described in the random access procedure of steps 103 to 105. In addition, the process shown in step 106 is further included: after the RACH message buffer queue is initialized, if the RACH message is not received again during the timing period of detecting the access timer, or even received within the timing period After the RACH message, the counter of the RACH message does not reach the preset access decision threshold (that is, when the reporting condition is not met after detecting the access timer expires), according to the current access detection timer. The serial number of the corresponding element is deleted.

The deleted elements mainly include: a random access message, the cache counter with an initial value of 1 for a random access message, an access detection timer corresponding to the random access message, a sequence number thereof, and an access decision threshold. According to the description of FIG. 3, the following two cases of the random access processing method are summarized as follows: In the first case, the RACH message buffer queue receives the RACH message for the first time, that is, the RACH message buffer queue is empty at the beginning. The RACH message is not included. When the RACH message is received for the first time, the element corresponding to the RACH message is added to the RACH message buffer queue, and the corresponding access detection timer is started. During the timing period of the timer, it is determined whether the count of the buffer counter at this time reaches the access decision threshold. If the access decision threshold has been reached, the BSC channel request message is reported and deleted from the RACH message cache queue. The element corresponding to the RACH message; if the RACH message is not received or the RACH message is received again during the entire timing period of the access detection timer, the count value of the buffer counter does not reach the access decision threshold. (Even if the timer expires, the count value of the RACH message has not yet reached the reporting condition, that is, the preset access decision threshold), the element corresponding to the RACH message is directly deleted from the RACH message buffer queue;

The second case is as follows: The RACH message buffer queue receives the RACH message for the first time, that is, the RACH message buffer queue is empty and does not contain the RACH message. In this case, when the RACH message is received for the first time, the RACH is received. The element corresponding to the message is added to the RACH message buffer queue, and the corresponding access detection timer is started. During the timing period of the access detection timer, it is determined whether the count of the buffer counter at this time reaches the access determination threshold. If not, continue to wait for the next RACH message within the timer period of the timer. If the RACH message is received again during the timing period of the access detection timer, the RACH message is cached in the queue. The count of the buffer counter is incremented by 1. When the count is the same as the decision threshold in the timing period, the BSC channel request message is reported, and the element corresponding to the RACH message is deleted from the RACH message buffer queue.

Therefore, the random access processing method of the present invention is to obtain the number of times of the buffer counter of the random access message in the random access message buffer queue in the timing period of the access detection timer corresponding to the random access message; Comparing the number of times of the buffer counter of the random access message with a preset access decision threshold; and performing a reporting of the base station controller channel request message and deleting the random access message buffer queue according to the comparison result An element corresponding to the random access message; or directly deleting an element corresponding to the random access message from the random access message buffer queue.

The timing of the access detection timer is determined by the number of transmission distribution slots tx_integer (T), the maximum number of retransmissions max_retran (M), the access decision threshold, and the channel combination parameter S, and the channel combination parameter S is based on the transmission distribution. Number of slots T and common control channel (Common Control Channel, the tube is called CCCH) The configuration is confirmed. The access detection timer timing period should be greater than the maximum duration of the M random access pulses sent by the mobile terminal.

The access decision threshold can be set to R according to the current cell traffic size (for example: configured as 3, 2 or 1). When the cell traffic is small, the frequency of occurrence of the pseudo random access pulse is high, preferably the maximum number of retransmissions M is set to 2, the number of transmission distribution slots T is set to 3, the common control channel and the independent dedicated control channel. (SDCCH, Stand-alone Dedicated Control Channel) is shared, the access decision threshold is set to 2, and the access detection timer timing period is set to 193.86 ms. Obtaining arbitrary by the above-mentioned maximum number of retransmissions M, channel combination parameter S (determined according to the number of transmission distribution slots (3) and the common control channel configuration (CCCH channel and SDCCH channel sharing) and the access determination threshold) The maximum number of time slots between two adjacent channel request messages is (S+T-1), and the maximum time interval for the same mobile terminal to continuously send RACH messages twice does not exceed 193.86 ms. Therefore, it is guaranteed that the same RACH message is received at least twice in the timing period, thereby ensuring effective filtering of the pseudo random access pulse.

As the traffic volume increases, the probability of occurrence of the pseudo-random access pulse is gradually reduced, and the number of times the mobile terminal retransmits the RACH message can be reduced, and the access decision threshold and the access detection timer timing period are adjusted accordingly.

After determining the access decision threshold and the timing period of the access detection timer, the parameter is added to the random access processing system for random access control.

Accordingly, the present invention also provides a random access processing system. As shown in FIG. 4, the method includes: a random access message buffer queue maintenance update module 40, configured to cache an element corresponding to the random access message, and obtain random in a timing period of the access detection timer corresponding to the random access message The number of times the buffer counter of the random access message in the message buffer queue is accessed; the number of times of the buffer counter of the random access message is compared with a preset access determination threshold; and the reporting base station is controlled according to the comparison result. And deleting the element corresponding to the random access message from the random access message buffer queue, or directly from the random access message The element corresponding to the random access message is deleted in the storage queue.

The system further includes a random access message control parameter maintenance module 41, configured to start an access detection timer corresponding to the random access message, and the cache counter and the random access message corresponding to the initial value of the random access message are The sequence number of the access detection timer and the traffic volume level on which the access decision threshold is based.

The random access message cache queue maintenance update module 40 is further configured to determine that the random access message is included in the random access message buffer queue, and increment the count of the cache counter of the random access message by one.

That is, the system of the present invention is composed of two modules: The RACH message control parameter maintenance module is used to maintain the filtering parameters of the updated pseudo random access pulse, including the counter access decision threshold, the timer timing period, the traffic level, and the like; The RACH message buffer queue maintenance update module is configured to buffer the random access pulse decoded by the base station, and determine whether to report the BSC channel request message. The module is driven by two events: receiving a RACH message reported by the channel processing unit, or the access detection timer times out. After the RACH message buffer queue maintenance update is completed, the module increases the count value of the counter of the RACH message received again by one. If the buffer counter of the current RACH message reaches the access determination threshold, the channel request message is reported to the BSC. And then enter the processing flow of the channel request message in the normal mode.

Compared with the prior art, the present invention solves the problem of reduced access efficiency and waste of communication resources caused by pseudo-random access pulses, and is an optimization of the RACH message processing flow applied to the actual system by the 3GPP protocol. Moreover, the present invention has no impact on the existing network structure and service implementation, and does not need to modify the existing interface specification, and has good compatibility and scalability.

It should be noted that the above embodiments are only intended to illustrate the technical solutions of the present invention, and the present invention is not limited thereto. The present invention will be described in detail with reference to the preferred embodiments. The spirit and scope of the technical solutions and claims of the present invention are not to be construed as being limited.

Claims

Claim

A random access processing method, comprising the steps of:

The number of times of the buffer counter of the random access message is compared with a preset access decision threshold; and the random access message is processed according to the comparison result.

The random access processing method according to claim 1, wherein when the comparison result is the number of times of the buffer counter of the random access message in the random access message buffer queue, the access decision threshold is reached. The value of the random access message processing includes:

The random access processing method according to claim 1, wherein when the comparison result is a judgment of the number of times of the buffer counter of the random access message in the random access message buffer queue, the access determination is not reached. The processing of the random access message includes: deleting an element corresponding to the random access message from the random access message buffer queue.

The random access processing method according to any one of claims 1 to 3, wherein the method further comprises:

The random access processing method according to claim 4, wherein the number of times of the buffer counter of the random access message in the random access message buffer queue is:

During the timing period of the access detection timer, the random access message is received again, and the count of the buffer counter of the random access message is incremented by one.

The random access processing method according to claim 5, wherein the deleting The element corresponding to the random access message includes: the random access message, a buffer counter whose initial value is 1 of the random access message, a sequence number of the access detection timer corresponding to the random access message, and the connection Enter the decision threshold.

The random access processing method according to claim 4, wherein the access determination threshold is set according to a traffic volume size.

The random access processing method according to claim 4, wherein the timing of the access detection timer is determined by the number of transmission distribution slots, the access determination threshold, and the maximum number of retransmissions, and The channel distribution parameter control determined by the number of transmission distribution slots and the common control channel configuration.

9. A random access processing system, characterized in that it comprises at least:

The random access message buffer queue maintenance update module is configured to cache an element corresponding to the random access message, and obtain the random in the random access message cache queue in a timing period of the access detection timer corresponding to the random access message The number of times the cache counter of the access message is compared; the number of times of the buffer counter of the random access message is compared with a preset access decision threshold; and according to the comparison result, the reporting of the base station controller channel request message is performed and from the random The element corresponding to the random access message is deleted from the access message buffer queue; or the element corresponding to the random access message is directly deleted from the random access message buffer queue.

The random access processing system according to claim 9, wherein the system further comprises: