CN1275425C - Upward bandwidth controlling method for wide band radio switching in system - Google Patents

Abstract

The invention discloses a method for controlling the uplink bandwidth of a broadband wireless access system in the field of data communication. Create an IP service configuration table for IP services, and then proceed to step 2 and step 3 at the same time; step 2: process the bandwidth request of the terminal: step 3: whenever the statistical cycle is scheduled, the total number of bytes sent by the terminal minus the earliest sliding The number of bytes sent in the window, and then the earliest item of the number of bytes sent in the sliding window is cleared to 0, and this step is repeated regularly. The present invention provides the functions of the minimum guaranteed bandwidth and the maximum limited bandwidth of the uplink, and at the same time makes the flow of uplink data sending smoother and the control of the bandwidth more accurate. In this way, the requirement for guaranteeing the quality of service of the uplink bandwidth of the system is better satisfied.

Description

Uplink Bandwidth Control Method for Broadband Wireless Access System

technical field

The invention relates to the communication field, in particular to a method for managing uplink air bandwidth in a broadband wireless access system.

Background technique

The broadband wireless access system mainly uses point-to-multipoint wireless transmission to realize the fixed wireless integrated service access function between the user network and the backbone network, and its service objects are mainly group users, such as enterprises, residential quarters and other users Integrated access system. The broadband wireless access system is divided into two parts, the base station and the terminal, and one base station corresponds to multiple terminals. The downlink channel is mainly broadcast, and the uplink channel is mainly shared by multiple users in a time-division manner. The access request of each user is controlled through the air interface protocol, that is, the terminal needs to make a request before sending uplink data, which is allocated by the base station. The terminal's data sending bandwidth and sending time.

In general, broadband wireless access systems need to provide QOS (Quality of Service Assurance) capabilities, especially the ability to provide different bandwidth services according to different levels of users, which inevitably involves uplink bandwidth control of broadband wireless access systems However, none of the existing broadband wireless access system protocols provides a method for realizing uplink bandwidth control, nor does it provide a principled requirement for realizing uplink bandwidth. Moreover, no bandwidth control method suitable for broadband wireless access systems can be found in the existing public materials. Although bandwidth control technologies exist in other existing communication systems, these technologies are not suitable for broadband wireless access systems. This leads to the defect that the existing broadband wireless access system cannot effectively control the uplink bandwidth and cannot fully meet the requirements for quality of service assurance.

technical content

The purpose of the present invention is to overcome the shortcomings in the prior art that the uplink bandwidth control method suitable for broadband wireless access systems cannot meet the quality of service guarantee capability, and provide a network that can effectively control the bandwidth according to the user level. The uplink bandwidth control method satisfies the uplink bandwidth service quality guarantee requirement of the broadband wireless access system.

In order to achieve the above object, the present invention proposes a method for controlling uplink bandwidth of a broadband wireless access system, including the following three steps:

Step 1: Establish an IP service configuration table: According to the configuration information of each terminal, establish an IP service configuration table for the uplink IP services of all terminals on the base station side, including the minimum guaranteed transmission bytes, maximum limited transmission bytes, Send the total number of bytes, the number of bytes sent in the sliding window and other related parameters; then proceed to step 2 and step 3 at the same time;

Step 2: Process the bandwidth request of the terminal, including the following steps:

Step 2-1: regularly collect uplink bandwidth requests from all terminals;

Step 2-2: Sort the terminal requests and the existing remaining general requests of the base station together, sort according to the calculation result of "number of transmitted bytes/minimum guaranteed bandwidth", and put the uplink bandwidth requests with small values in front;

Step 2-3: Process the priority request queue, modify the IP service configuration table at the same time, add the sent bytes of all allocated requests to the parameter items of the sent bytes of the current sliding window and its total sent bytes ;

Step 2-4: Process the general request queue, search the general request queue twice, and find out the bandwidth requests whose sent bytes are less than the minimum guaranteed sent bytes in the first pass, and allocate them directly if there is enough free bandwidth , otherwise put the terminal into the priority request queue and wait for priority processing next time; at the same time, modify the parameters of the terminal in the IP service configuration table, and add the sent bytes of all allocated bandwidth requests to its current sliding window sending Parameter items for the number of bytes and their total sent bytes;

Step 2-5: If there is still free bandwidth, perform a second search on the remaining bandwidth requests, find out the bandwidth requests whose number of bytes sent is less than the maximum number of bytes sent, and allocate bandwidth to the terminal that made the bandwidth request; Modify the IP service configuration table at the same time, and modify the parameters of the terminal in the IP service configuration table at the same time, and add the number of sent bytes of all allocated bandwidth requests to the number of sent bytes of its current sliding window and its total sent bytes number of parameter items;

Step 2-6: Suspend the remaining requests and go to step 2-1;

Step 3: Whenever the statistical cycle is scheduled, the total number of bytes sent by the terminal is subtracted from the number of bytes sent in the earliest sliding window to obtain the updated total number of bytes sent, and then the number of bytes sent in the earliest sliding window The number of sent bytes item is cleared to 0, and this step is repeated regularly.

The present invention introduces a plurality of sliding windows and sets an IP service configuration table, and at the same time provides functions of uplink minimum guaranteed bandwidth and maximum limited bandwidth, and at the same time makes uplink data transmission flow smoother and bandwidth control more accurate. In this way, the requirement for guaranteeing the quality of service of the uplink bandwidth of the system is better satisfied.

Description of drawings

Figure 1 is a flow chart of the method of the present invention.

Fig. 2 is an example diagram of the sliding window of sent bytes according to the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Accompanying drawing 1 is the flowchart of the method of the present invention. In fact, in step 1, the configuration information of each terminal includes the minimum guaranteed bandwidth and the maximum restricted bandwidth, where the minimum guaranteed bandwidth refers to the guaranteed bandwidth promised by the operator to the terminal, which can allow a certain line ratio (the system may actually provide The bandwidth is 10M, but since each user usually does not send data at the same time, the bandwidth has a certain dynamic multiplexing, so the operator is allowed to sell 100M to the user, and the line ratio is 10:1 at this time). When the system bandwidth is insufficient, Each terminal is reduced in proportion to the configuration. The maximum restricted bandwidth refers to the maximum allowed occupied bandwidth of the terminal, even if the system still has remaining bandwidth, the terminal is not allowed to exceed this limit. In addition, N sliding windows are established for each terminal on the base station. The larger the number of sliding windows, the more accurate the flow control is, but the lower the execution efficiency is, the more resources are consumed. The initial value of all sliding windows is 0. In each statistical period, when the terminal has data to send, the number of bytes sent is added to the number of bytes sent in the current sliding window. When the statistical cycle is timed, the data in the earliest sliding window is cleared to 0, and the current sliding window pointer points to the next window. The total number of bytes sent is the sum of the values in all sliding windows of the terminal, that is, the sum of the number of bytes sent by the terminal within a period of time such as the statistical period × the number of sliding windows N, and the initial value is 0. When the terminal has data to send, it adds the number of bytes sent to the current sliding window and adds the total number of bytes sent at the same time. When each statistical period arrives, the total sent bytes of the terminal will be subtracted from the sent bytes in the earliest sliding window, and then the earliest sliding window will be cleared to 0. In this way, the total number of bytes sent is still the sum of the number of bytes sent in all sliding windows of the current terminal. The uplink IP service of each terminal refers to the service entering the terminal through the Ethernet port, and the service conforms to the TCP/IP protocol. The relevant parameters recorded in the IP service configuration table established in step 1 are shown in the following table: Minimum Guaranteed Bytes maximum limit bytes Total bytes sent Send bytes in each sliding window Terminal 1 Terminal 2 ... ... terminal n

Among them, the minimum guaranteed sending bytes of each terminal refers to the number of bytes guaranteed to be sent by the terminal within 1 second, which is the minimum guaranteed bandwidth × 1 second ÷ 8, and the unit is bytes; the maximum limited sending bytes refers to 1 The maximum number of bytes that the terminal can send within a second is the maximum bandwidth limit × 1 second ÷ 8, in bytes; the total number of bytes sent refers to the sum of the number of bytes sent within each sliding window; The number of bytes means that the size of the sliding window is the same as the statistical period, usually 100 milliseconds, and the number of bytes sent within a certain sliding window refers to the number of bytes sent by the terminal within a certain interval of 100 milliseconds.

In step 3, whenever the statistical cycle is timed (usually the cycle can be selected as about 100 milliseconds), the total sent bytes of the terminal are subtracted from the sent bytes in the earliest sliding window, and then the earliest sliding window is cleared to 0 . Each execution of step 3 updates the total sent bytes, and this result is used in steps 2-4 and 2-5.

The purpose of ordering the requests in step 2-2 is to ensure that the terminals with the same minimum guaranteed bandwidth configuration have basically the same actual bandwidth when the bandwidth is insufficient, and the actual bandwidth occupied by terminals with different minimum guaranteed bandwidth configurations is basically proportionally reduced when the bandwidth is insufficient.

Step 2-3 The priority request queue is the last request that has met the sending conditions, but was not successfully allocated due to insufficient real-time bandwidth of the system, but the number of sent bytes is less than the minimum guaranteed number of sent bytes, so this time it is being processed Priority is given to other general requests.

Steps 2-4 and 2-5 perform two retrievals on general requests (requests other than priority sending requests) in order to allocate the requests whose occupied bandwidth is less than the minimum guaranteed bandwidth in this statistical period for the first time, The second reassigns other requests whose occupied bandwidth is within the maximum bandwidth limit.

Steps 2-6 suspend the remaining requests for next processing. There are two situations for remaining requests. The first one is that there is no remaining bandwidth, so the following requests will not be processed. The second one is that the number of bytes sent by the terminal is greater than the maximum number of bytes sent, and the request is temporarily not allowed. The terminal sends again, and waits until the next statistical cycle arrives to reduce the number of bytes sent, and then continue sending if it is less than the maximum number of bytes sent. Return to step 2-1 after step 2-6 is completed. The purpose of suspending the request is to indicate that the base station has received the bandwidth request from the terminal, but since there is no free bandwidth at present or the bandwidth occupied by the terminal has exceeded the maximum bandwidth limit, it will not be processed at present, and the terminal does not need to repeat the request up.

It should be noted that, steps 2-1 to 2-6 are the request processing process, and this process is cyclical, and step 2-1 is followed after step 2-6 is completed. Also, since the request processing process is generally different from the timer in step 3, steps 2-1 to 2-6 are not always processed serially after step 3, but are processed in parallel with step 3 .

Figure 2 describes the changing process of the sliding window in the IP service parameter configuration table of a certain terminal during the normal operation of the broadband wireless access system. Assuming that the bandwidth is controlled in units of 1 second, the statistics are re-stated every 100 milliseconds, so there are 10 sliding windows in total. At the beginning, the total number of sent bytes is 0, and the number of bytes in the sliding window is also 0. Here, 1 second, 100 milliseconds, and 10 sliding windows are just examples, and the actual application is not limited thereto.

When the allocated bandwidth request of a certain terminal is satisfied, the number of bytes sent by the terminal is added to the current sliding window and also added to the total sent bytes. If the total number of bytes sent at this time has exceeded the number of bytes allowed to be sent by the terminal within 1 second, the terminal is no longer allowed to send. When the statistical period of 100 milliseconds expires, subtract the number of bytes sent in the earliest sliding window from the number of bytes sent, move the pointer of the current sliding window down, and clear the number of bytes in it. It can be seen from Figure 2 that after 1000 milliseconds, all 10 sliding windows have sent data, and at this time, it can be seen that the earliest sliding window is cleared to 0 every 100 milliseconds. The total sent bytes in the current time period also changes accordingly.

If this method of sliding window is not used, only a total number is used for statistics. If it is counted once in 1 second, then the transmission may be concentrated in the first part of the statistics period, and the traffic will be very uneven; if it is reduced to 100 milliseconds, the statistics will be once , the traffic is smooth compared to the statistical period of 1 second, but the bandwidth control is not accurate. For example, if the bandwidth of a terminal is 1Mbit/s, then 100Kbit is allowed to be sent every 100 milliseconds. If the burst traffic is 500kbit within a certain 100 milliseconds, No data was sent in the previous 900 milliseconds, but the terminal can still only send 100kbit in the current 100 milliseconds. In this way, the bandwidth in the previous second is 100kbit/s, which has not reached the user's bandwidth limit, but at this time the error is limited sent from this terminal. But adopting the sliding window method described in the present invention will not have the above-mentioned problems, what is always controlled is the current bandwidth within 1 second, the control is accurate, and the flow is smooth.

The present invention better satisfies the requirements for system uplink bandwidth service quality assurance, the terminals with the same minimum guaranteed bandwidth configuration actually occupy the same bandwidth when the bandwidth is insufficient, and the terminals with different minimum guaranteed bandwidth configurations actually occupy the bandwidth when the bandwidth is insufficient decreased proportionally. At the same time, the upstream data transmission flow is smoother, and the bandwidth control is more accurate.

Claims (5)

1, a kind of BWA upstream bandwidth control method is characterized in that, may further comprise the steps:

Step 1: set up the IP operation allocation list: according to the configuration information of each terminal, set up the IP operation allocation list for the up IP operation of all terminals, carry out step 2 and step 3 then simultaneously in base station side;

Step 2: the bandwidth request of processing terminal specifically comprises:

Step 2-1: regularly collect the uplink bandwidth request that all terminals are sent;

Step 2-2: the existing remaining general request of terminal request and base station is sorted jointly, and the uplink bandwidth request that value is little comes the front;

Step 2-3: handle the override requests formation, revise the IP operation allocation list simultaneously, the transmission byte number of all requests that distributed is joined transmission byte number and total parameter project that has sent byte number thereof of its current sliding window;

Step 2-4: handle general request queue, this general request queue is retrieved, found out and send the bandwidth request of byte number, then directly distribute if any enough idle bandwidths less than minimum assurance transmission byte number, otherwise this terminal is put into the override requests formation, treat next priority treatment; Revise the parameter of this terminal in the IP operation allocation list simultaneously, the transmission byte number of all bandwidth request of having distributed is joined transmission byte number and total parameter project that has sent byte number thereof of its current sliding window;

Step 2-5: if also have idle bandwidth, then second time retrieval carried out in the remaining bandwidth request, found out the byte number that sent and send the bandwidth request of byte number, for proposing the terminal distribution bandwidth of this bandwidth request less than maximum; Revise the IP operation allocation list simultaneously, revise the parameter of this terminal in the IP operation allocation list simultaneously, the transmission byte number of all bandwidth request of having distributed is joined transmission byte number and total parameter project that has sent byte number thereof of its current sliding window;

Step 2-6: the request of will remaining is hung up, and changes step 2-1;

Step 3: when measurement period is timed to, terminal has sent total bytes and has deducted and send byte number in the earliest the sliding window, the total byte number of transmission that has obtained upgrading, it is clear 0 to send the byte number project in then will sliding window the earliest, and this step regularly repeats.

2, BWA upstream bandwidth control method according to claim 1 is characterized in that, the measurement period in the described step 3 is 100 milliseconds.

3, BWA upstream bandwidth control method according to claim 1 is characterized in that, the ordering rule among the described step 2-2 carries out according to the result of calculation of " sent byte number/minimum and guaranteed bandwidth ".

4, BWA upstream bandwidth control method according to claim 1, it is characterized in that described IP operation allocation list parameter comprises that the minimum of each terminal guarantee to send byte, maximum constraints and sends byte, sends and send byte number in total bytes, the sliding window.

5, BWA upstream bandwidth control method according to claim 1 is characterized in that, the initial value of described sliding window is zero.

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