KR100952679B1 - CBS message transmitting method and mobile communication system using the same - Google Patents

Abstract

Disclosed are a cell broadcast service message transmission method in a mobile communication system and a WCDMA mobile communication system using the same. In the method for transmitting a cell broadcast service message in a mobile communication system according to the present invention, the method comprising: determining a step of comparing a data size of a CBS message for broadcasting with a preset reference value, and transmitting a CBS message corresponding to the compared result; Dynamically determining, transmitting the determined transmission period to the SIB to change the SIB value, and notifying the mobile communication terminal of the change of the SIB value using a paging message. Thus, the CBS message can be efficiently transmitted to the mobile communication terminal in the WCDMA mobile communication system.

WCDMA, CBS, SIB, Transmission Cycle, Data Volume

Description

Method of transmitting cell broadcast service message in mobile communication system, mobile communication system using same, and interface protocol structure thereof {CBS message transmitting method and mobile communication system using the same}

The present invention relates to a cell broadcast service message transmission method in a mobile communication system, a mobile communication system using the same, and an interface protocol structure thereof. More specifically, the present invention relates to a CBS (Wideband Code Division Multiple Access) method in a mobile communication system. The present invention relates to a cell broadcast service message transmission method in a mobile communication system for efficiently transmitting a cell broadcast service message to a mobile communication terminal, a WCDMA mobile communication system using the same, and an interface protocol structure thereof.

Today, due to the development of the telecommunications industry, the services provided by the mobile communication system are developing not only voice services but also multicasting multimedia communication that transmits large data such as packet data and circuit data. In addition, there is a broadcast / multicast service that provides a service from one data source to a plurality of user equipments (UEs) in order to support such multicasting multimedia communication. Such a broadcast / multicast service is a cell broadcast service (CBS), a message-oriented service, and a multimedia broadcast / multicast service (Multimedia Broadcast /) supporting multimedia forms such as real-time video, audio, still images, and text. Multicast Service (MBMS). Hereinafter, a cell broadcast service related to a BMC layer will be described.

A service that sends and receives messages composed of letters and numbers between terminals or between a terminal and a network is called a short message service (SMS). Such SMS is further divided into Cell Broadcast Short Message Service (SMS-CB) and Point-to-Point Short Message Service (SMS-PP) services that send the same short message to one or more cells. Here, the CBS service corresponds to the SMS-CB service, and refers to a service of broadcasting a plurality of CBS messages to all users of a specific region.

CBS messages are user messages consisting of letters and numbers. One CBS message consists of one or more pages (up to 15 pages). One page consists of 82 octets, which is equivalent to 93 characters of information. CBS messages are broadcast in a geographic area called the cell broadcast area. These regions consist of one or more cells or an entire PLMN. Individual CBS messages are broadcast to the geographic area by a mutual contract between the information provider and the PLMN operator.

The broadcast message period is determined by the value of N for the CBS message. For example, when N = 6, as shown in FIG. 1, when data is transmitted in one SCCPCH frame, the next five SCCPCH frames are rested and a CBS message is transmitted in the sixth SCCPCH frame. Done. In general, in case of N, data is transmitted in N-1 frame when transmitted in random frame.

In a WCDMA mobile communication system, an N value, which is a period of transmitting a CBS message, is generally broadcast through SIB (System Information Block) 5, and the N value is set to a fixed value. However, when the N value is set to small, broadcast data can be transmitted at a high transmission rate, but the power consumption is increased due to the reception of frequent SCCPCH frames. When the N value is set to a large value, the power consumption is reduced, but many slots are used. There is a problem in that a lot of time delay occurs in transmitting a broadcast message because the broadcast is stopped.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a cell broadcast service message transmission method and a method for transmitting the same in a mobile communication system for efficiently transmitting a CBS message to a mobile communication terminal in a WCDMA mobile communication system An object of the present invention is to provide a mobile communication system using a WCDMA system and an interface protocol structure thereof.

In the method for transmitting a cell broadcast service message in a mobile communication system according to the present invention for achieving the above object, (a) determining a step of comparing a data size of a CBS (Cell Broadcast Service) message for broadcasting with a preset reference value; Making; (b) dynamically determining a transmission period of the CBS message corresponding to the result compared by step (a); (c) changing the SIB value by transmitting the transmission period determined by step (b) to a system information block (SIB); And (d) informing the mobile communication terminal of the change of the SIB value by the step (c) using a paging message, wherein the transmission period of the CBS message is in a Secondary Common Control Physical Channel (SCCPCH). Characterized in that it is a common traffic channel (CTCH) allocation cycle.

Here, it is preferable that the transmission period of the CBS message is smaller as the data size of the CBS message is larger.

In addition, the transmission period of the CBS message is preferably determined larger the smaller the data size of the CBS message.

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In this case, the data size of the CBS message has a step value that increases in the order of 1, 2, 3, ... K (K is a natural number) corresponding to a reference value that decreases from a maximum value, and the transmission period of the CBS message is be determined by 2 ^K are preferred.

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The air interface protocol structure according to the present invention for achieving the above object, comparing the data size of the CBS message for broadcasting with a predetermined reference value, and dynamically determines the transmission period of the CBS message corresponding to the comparison result Broadcast Multicast Control (BMC) layer; A Radio Link Control (RLC) layer for changing a SIB value by transmitting a transmission period of the CBS message determined by the BMC layer to an SIB; And a medium access control (MAC) layer for notifying the mobile communication terminal of the change of the SIB value using a paging message, wherein the transmission period of the CBS message is determined as a CTCH allocation period in SCCPCH.

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In addition, the MAC layer is preferably notified to the mobile communication terminal that the SIB value is changed by using a Broadcast Control Channel (BCCH) field in the paging message.

According to the present invention, since the transmission period of the CBS message can be dynamically changed and broadcasted according to the amount of data of the CBS message, the broadcast service of the CBS message can be efficiently provided.

Hereinafter, a method of transmitting a cell broadcast service message in a mobile communication system and a WCDMA mobile communication system using the same will be described in detail with reference to the accompanying drawings.

In general, mobile communication is classified into a first generation (cellular system), a second generation (Personal Communication Service (PCS)), and a third generation (Universal Mobile Telecommunication System (UMTS)). Is used together.

The third generation of UMTS is a mobile communication system capable of high performance transmission and reception suitable for mobile computing capable of providing a multimedia service including voice and video, and one of several methods for implementing the system is WCDMA. That's the way. This approach has been standardized in the 3rd Generation Partnership Project (3GPP), a standardization project in Europe, Korea, Japan, the United States, and China, and is expected to be adopted in many countries.

2 is a diagram illustrating a network structure of a UMTS system. The UMTS system is composed of a user equipment (UE), a UMTS Terrestrial Radio Access Network (UTRAN), and a core network (CN).

Among them, the UTRAN is composed of one or more Radio Network Sub-systems (RNS), and each RNS is composed of a Radio Network Controller (RNC) and one or more base stations managed by the RNC. do. Each base station has one or more cells.

3 illustrates a structure of a radio interface protocol between a terminal and a UTRAN based on the 3GPP radio access network standard. The air interface protocol of FIG. 3 horizontally consists of a physical layer, a data link layer, and a network layer, and vertically a user plane for transmitting data information. ) And a control plane for transmitting control signals. Such protocol layers may be divided into a first layer, a second layer, and a third layer based on the lower three layers of the Open System Interconnection (OSI) reference model that are widely known in communication systems.

The physical layer, which is the first layer, provides an information transfer service to an upper layer by using a physical channel. The physical layer is connected to the upper Media Access Control (MAC) layer through a transfer channel, and data is transferred between the media access control layer and the physical layer through the transport channel. . Then, data moves between different physical layers, that is, between physical layers of a transmitter and a receiver.

The media access control layer of the second layer provides a service to a radio link control (RLC) layer, which is a higher layer, through a logical channel. The radio link control layer supports reliable data transmission and performs a segmentation and concatenation function of an RLC Service Data Unit (SDU) from an upper layer.

The broadcast / multicast control (BMC) layer of the second layer may perform a function of scheduling a cell broadcast (CB) message transmitted from a core network and broadcasting to UEs located in a specific cell. do. In terms of UTRAN, the CB message transmitted from the upper layer is transmitted to the RLC layer in the form of a BMC message by adding information such as message ID, serial number, coding scheme, and the like. Channel) to the MAC layer. The logical channel CTCH is mapped to the transport channel forward access channel (FAC) and physical channel secondary common control physical channel (SCCPCH).

The Packet Data Convergence Protocol (PDCP) layer of the second layer is located above the RLC layer, and data transmitted through a network protocol such as IPv4 or IPv6 can be efficiently transmitted over a relatively small bandwidth wireless interface. To be possible. To this end, the PDCP layer reduces the unnecessary control information used in the wired network. This function is called header compression, and header compression defined by the Internet Standardization Group called the Internet Engineering Task Force (IETF). Techniques RFC2507 and RFC3095 (Robust Header Compression (ROHC)) can be used. These methods allow only the necessary information to be transmitted in the header portion of the data, thereby transmitting less control information, thereby reducing the amount of data to be transmitted.

The radio resource control (RRC) layer located at the bottom of the third layer is defined only in the control plane, and configures, re-configures, and releases of radio bearers (RBs). is responsible for controlling logical channels, transport channels, and physical channels. In this case, the RB refers to a service provided by the second layer for data transmission between the UE and the UTRAN, and in general, the RB is configured to define characteristics of protocols and channels required to provide a specific service, and each specific Refers to the process of setting parameters and operation methods.

4 is a flowchart illustrating a method of transmitting a cell broadcast service message in a mobile communication system according to the present invention.

Referring to the figure, the BMC layer of the mobile communication system compares the data size of the CBS message temporarily stored in a buffer (not shown) with a preset reference value for broadcasting (S101). At this time, the reference value is preferably set to a plurality of values smaller than the maximum value with respect to the maximum storage capacity of the buffer. For example, when the maximum capacity of the buffer is 100kbyte, the reference value may be set in stages such as 80kbyte, 60kbyte, 40kbyte, and 20kbyte.

As described above, with respect to the reference value set in steps, the data size of the CBS message stored in the buffer is one step when the maximum value is between the first reference value (80 kbytes in the above description), and the first reference value and the second reference value (as described above). 60 kbytes in the case of a description, the second stage value, and between the second reference value and the third reference value (40 kbytes in the above-described description) may be divided into three stages, and K stages (where K is a natural number). .

In addition, it is preferable that a transmission cycle of different CBS messages is set in each of the step values divided as described above. At this time, the transmission period of the CBS message is determined to be smaller the larger the data size of the CBS message stored in the buffer, it is preferable that the larger the data size of the CBS message stored in the buffer is larger. That is, as the data amount of the CBS message stored in the buffer decreases from step 1 to step K with respect to the buffer capacity as shown in FIG. 5, it is preferable that the transmission period of the CBS message is larger.

The BMC layer of the mobile communication system determines the transmission period of the CBS message according to the result of comparing the data amount of the CBS message for broadcasting with a reference value, that is, a step value for the data amount of the CBS message (S103).

At this time, two threshold values of the upper limit and the lower limit of the data amount of the CBS message temporarily stored in the buffer (for example, in the case of the above description, if the data amount of the CBS message stored in the buffer is 70kbyte, the threshold is 80kbyte and If the amount of data in the CBS message stored in the buffer exceeds the upper limit threshold, the transmission cycle of the CBS message is lowered to one level smaller, and the data amount of the CBS message stored in the buffer is lower than the threshold. If smaller, the transmission period of the CBS message is increased by one step. However, if the amount of data in the CBS message stored in the buffer is divided into too many stages, the ping-pong phenomenon may occur in which the CBS message transmission cycle is changed too frequently. Therefore, the amount of data in the CBS message is divided into three stages. It is preferable that only two threshold values, a period limit upper limit and a lower limit, are set. In this case, it is preferable that each threshold value of the upper limit and the lower limit is set to a value that is three times the maximum storage capacity of the buffer.

Preferably it is, that the transmission period of the CBS message is decided CTCH allocation in SCCPCH, when the amount of the CBS message data also has a step value corresponding to a reference value, such as 5, the interval of transmission of a CBS message is determined to be 2 ^K desirable. That is, when it is determined that the data amount of the CBS message is reduced from the first step to the second step, as shown in FIG. 6, the transmission period N of the CBS message is preferably changed to increase from 2 to 4. Further, when the amount of data increases CBS message in Step K by K-1 steps, and the other way around, it is the transmission period of the N CBS message is preferably determined, which change is smaller in the 2 ^K to 2 ^K-1.

The transmission period of the changed CBS message is transmitted to SIB5 to change the value of SIB5 (S105). In this case, it is preferable that the fact that the value of SIB5 has been changed is transmitted to the mobile communication terminal using the paging message (S107). That is, it is preferable that the MAC layer informs the mobile communication terminal that SIB5 has been changed by using a Broadcast Control Channel (BCCH) field in the paging message, so that the mobile communication terminal can recognize the changed transmission cycle of the CBS message.

As described above, the WCDMA mobile communication system according to the present invention broadcasts by dynamically determining the transmission period of the CBS message according to the data amount of the CBS message stored in the buffer for broadcasting, and thus, when the broadcast amount is large, If the broadcast speed is changed and broadcast is small, the time delay can be appropriately increased to reduce power consumption.

Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the present invention is not limited to the specific embodiments of the present invention without departing from the spirit of the present invention as claimed in the claims. Anyone skilled in the art can make various modifications, as well as such modifications are within the scope of the claims.

1 is a view illustrating a transmission period of a general CBS message;

2 is a diagram illustrating a network structure of a UMTS system;

3 is a diagram showing the structure of a radio interface protocol between a UE and a UTRAN based on the 3GPP radio access network standard;

4 is a flowchart illustrating a method of transmitting a CBS message in a mobile communication system according to the present invention;

5 shows the amount of data in a CBS message for a buffer, and

FIG. 6 is a diagram illustrating a change in a transmission period of a CBS message corresponding to the data amount of the CBS message of FIG. 5.

Claims (10)

(a) determining a step of comparing a data size of a CBS (Cell Broadcast Service) message for broadcasting with a preset reference value; (b) dynamically determining a transmission period of the CBS message corresponding to the result compared by step (a); (c) changing the SIB value by transmitting the transmission period determined by step (b) to a system information block (SIB); And (d) notifying the mobile communication terminal of the change of the SIB value by the step (c) using a paging message; The transmission period of the CBS message is a cell traffic service message transmission method in a mobile communication system, characterized in that the common traffic channel (CTCH) allocation period in the Secondary Common Control Physical Channel (SCCPCH). The method of claim 1, The CBS message transmission cycle is determined as the data size of the CBS message is larger, the cell broadcast service message transmission method in a mobile communication system. The method of claim 1, The CBS message transmission period is determined as the data size of the CBS message is smaller, the cell broadcast service message transmission method in a mobile communication system. delete The method of claim 1, The data size of the CBS message has a step value that increases in the order of 1, 2, 3, ... K (K is a natural number) corresponding to a reference value that decreases from a maximum value. Cell broadcast service message transmitting method in a mobile communication system, characterized in that determined by the transmission period is 2 ^K of the CBS message. delete delete A broadcast multicast control (BMC) layer for comparing a data size of a CBS message for broadcasting with a preset reference value and dynamically determining a transmission period of the CBS message corresponding to the compared result; A Radio Link Control (RLC) layer for changing a SIB value by transmitting a transmission period of the CBS message determined by the BMC layer to an SIB; And A medium access control (MAC) layer for notifying the mobile communication terminal of the change of the SIB value using a paging message; The transmission period of the CBS message is determined by the CTCH allocation period in SCCPCH. delete The method of claim 8, And the MAC layer notifies the mobile communication terminal that the SIB value has been changed by using a Broadcast Control Channel (BCCH) field in a paging message.

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