KR20020052769A - Method for saving MP3 file automatically in N-WLL terminal unit - Google Patents

Abstract

PURPOSE: A method for automatically storing MP3(MPEG(Moving Picture Experts Group) layer 3) files of an N-WLL(Narrowband-Wireless Local Loop) terminal is provided to allow the N-WLL terminal to automatically capture the MP3 files and store the MP3 files in a memory module, without using an external device such as a UART(Universal Asynchronous Receiver/Transmitter) or changing the memory module. CONSTITUTION: Whether the wireless call processing between a terminal and a base station is a data service is decided(S11). If not, voice call processing is performed(S12), and if a data service, whether a memory pool of the terminal has a margin is decided(S13). If not, data stored in the memory pool are all deleted and the step of S11 is repeated(S14), and if the memory pool has a margin, whether the received data is a frame header of an MP3 file is decided(S15). If not, general data service call processing is performed(S16) and the step of S13 is performed, and if the data correspond to a frame header of an MP3 file, a frame length check and a CRC(Cyclic Redundancy Check) are performed(S17). Whether frame length is checked is decided(S18). If not, the step of S16 is performed, and if checked, whether a result value of the CRC is coincident with the frame length is decided(S19). If not, the step of S16 is performed, and if coincident, the MP3 file is regarded as correct and stored in a memory module, namely, the memory pool of the terminal(S20).

Description

Method for saving MP3 file automatically in N-WLL terminal unit

The present invention relates to a narrowband wireless subscriber network system, and more particularly, to allow subscribers to store MP3 files in a terminal without directly connecting a PC and a terminal or replacing a memory module using an external device (UART port). The present invention relates to a method for automatically storing MP3 files in a narrowband wireless subscriber network terminal.

In general, WLL (Wireless Local Loop) is a technology that provides a subscriber line wirelessly, unlike the existing wired subscriber network connected the switch and the individual subscribers through a wired subscriber line. After the development of RF technology and the development of semiconductor and wireless communication technology in the late 1980s, the previous problems such as frequency efficiency, wireless channel quality, and cost per subscriber were solved. In addition, WLL is easier to construct subscriber lines than existing wired subscriber networks, and can be used as an emergency subscriber line in preparation for natural disasters, and can provide various services such as POTS, data, and ISDN.

Due to the above advantages, WLL is emerging as a communication infrastructure of developing countries, where new operators can secure subscriber networks early and establish new subscribers quickly even in urban areas. In particular, WLL has a poor wired network structure. Products developed for WLL include satellite system, fixed microwave system, cellular technology system, and cordless system system. It is used.

The system employing this cellular technology includes three multiple access schemes: Frequency Division Multiple Access (FDMA), Time Division Multiple Access (CDMA), and Code Division Multiple Access (CDMA). Division Multiple Access) is used. Commercially available products include FDMA and TDMA, but they are shifting to CDMA, which has a much larger subscriber capacity than other access methods.

WLL has similar characteristics to mobile communication network in terms of using wireless channel as a communication medium, but since there is no mobility, WLL network has much better radio environment than mobile communication network. It has the same characteristics.

First, the propagation environment of the mobile communication network is located at the position where the antenna height is lower than the surrounding buildings. As a result, it becomes a non-line-of-sight environment, which is caused by blocking, reflection, and diffraction of straight waves by surrounding buildings. Although the radio wave path loss is about 40dB / decade, the radio wave environment of the WLL network can be installed in a high place such as on the roof of a building, so the line-of-sight environment is secured so that the radio wave path loss is about 20dB / decade. It is small and can serve a wider area with the same transmission power.

Second, since the radio wave environment of the WLL network is point-to-point fixed communication, fading due to multipath is much less than that of the point-to-point mobile communication network. Eb / No required under mobile communication radio wave environment using 30KHz channel bandwidth is 18dB, but Eb / No required under radio wave environment of WLL network using same channel bandwidth is only about 14dB required for low power transmitter Do.

Third, since the WLL network is a fixed wireless communication network, no handoff occurs. Therefore, it is not necessary to secure an extra handoff radio channel required for communication service without disconnection in the mobile communication network, and the WLL network does not need it. This extra radio channel can be used for general call use, increasing the efficiency of the radio channel and accommodating subscribers. The effect of increasing the dose can be obtained. In addition, the wireless link between each building and the base station can be established in a direction to reduce interference to a particular subscriber. Since the wireless link is unchanged unless the subscriber increases too much or the cell is divided after being installed, the wireless link does not change. The design is much simpler than a mobile network.

Fourth, since the WLL network is fixed wireless communication, it is possible to reduce the influence of co-channel interference on individual subscribers by using a directional antenna for the forward / reverse link, thereby reducing the frequency reuse distance. The reduction in frequency reuse distance results in an increase in subscriber capacity per unit area.

The wireless subscriber network system can be classified into a narrowband wireless subscriber network system (Narrowband WLL) and a wideband wireless subscriber network system (Wideband WLL), both of which use CDMA. In particular, the narrowband wireless subscriber network system, that is, the N-WLL has a bandwidth of 1.25MHz and mainly processes voice, and can transmit and receive files, fax, and access the Internet at a speed of 14.4 kbps.

A schematic configuration of such a general narrowband wireless subscriber network system is shown in FIG. That is, as shown, the subscriber's data terminal 10, such as a computer or a fax, is directly connected to the N-WLL terminal 11. The N-WLL terminal 11 has the same function as the CDMA mobile terminal except for the handoff function, and is wirelessly linked with the base station to provide voice and data services to the subscriber.

The base station 12 receives voice and data signals from an N-WLL terminal and interworks with an interworking function (IWF) 13 and a public telephone network (PSTN) 14 to communicate with the other terminal 15. Perform the transmission and reception. Here, the IWF 13 has a modem function and interworks with a public telephone network so that data communication is possible.

In the configuration of the narrowband wireless subscriber network system, that is, the N-WLL, the terminal connected to the subscriber terminal may be a computer, a fax, or a telephone.

Data services that can be provided using a fax or a computer connected to a terminal of the narrowband wireless subscriber network system include MP3, which is an audio file format in response to the recent multimedia orientation.

In the related art, in order to store MP3 files downloaded from the Internet in a wireless mobile communication terminal, MP3 files stored in a PC can be used by using a UART (Universal Asynchronus Receiver / Transmitter) port of the terminal or an MP3 memory module. ) Was used.

However, the conventional technology as described above has a problem in that a user directly connects a PC and a terminal to move an MP3 file. In addition, there is a problem in that additional costs such as a UART cable or a memory module to store the MP3 file in the terminal.

Therefore, the present invention has been proposed to solve the above problems according to the prior art,

An object of the present invention is to check the MP3 file through the frame length and the cyclic redundancy test when the data is input to the narrowband wireless subscriber network terminal, and automatically stores the data in the memory module of the terminal to the user by using an external device (UART port) The present invention provides a method of automatically storing MP3 files in a narrowband wireless subscriber network terminal that allows MP3 files to be stored in the terminal without directly connecting a PC to the terminal or replacing a memory module.

A feature of the MP3 file automatic storage method of the narrowband wireless subscriber network terminal according to the present invention for achieving the above object,

A first step of determining whether the radio call processing between the narrowband wireless subscriber network terminal and the base station is a data service;

A second step of performing general voice call processing if it is not a data service and determining whether there is free storage capacity of a memory pool if it is a data service;

As a result of the determination of the second step, if there is no free storage capacity of the memory pool, all stored data is deleted. If there is free storage capacity of the memory pool, the received data is a frame header of an MP3 file. Determining a cognition;

As a result of the determination in the third step, if it is not the frame header of the MP3 file, the general data service is performed again to determine whether the storage capacity of the memory pool remains, and if the received data is the frame header of the MP3 file, A fourth step of checking a frame length and a cyclic redundancy check;

A fifth step of determining whether the length of the frame is checked; if not, performing general data service; and if the length of the frame is confirmed, determining whether a result of the cyclic redundancy check matches the length of the frame Wow;

As a result of the determination in the fifth step, if the result of the cyclic redundancy check does not match the length of the frame, general data service is performed. If the result of the cyclic redundancy check matches the length of the frame, the correct MP3 file format is performed. In this regard, the method includes a sixth step of storing the memory module in a memory module of the terminal.

1 is a schematic configuration diagram of a general narrowband wireless subscriber network system,

2 is a block diagram illustrating a data service of a typical narrowband wireless subscriber network system;

3 is a flowchart illustrating a method for automatically storing MP3 files in a narrowband wireless subscriber network terminal according to the present invention.

<Explanation of symbols for the main parts of the drawings>

11: terminal

13: IWF

51: serial driver

54: AT command processor

59: RLP (Radio Link Protocol)

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the method for automatically saving the MP3 file of the narrowband wireless subscriber network terminal according to the present invention will be described in detail.

2 is a block diagram illustrating a data service of a typical narrowband wireless subscriber network system.

As shown in the drawing, the data service unit 52 and the protocol service unit 53 are interoperable with a protocol stack such as the AT command processor 54 or the RLP (Radio Link Protocol) 59 by receiving a command from the call processing unit 50. To process the data stream.

In addition, the serial driver 51 is for interfacing with the serial port of the user's PC during the data service of the N-WLL terminal, the AT command processor 54 is for processing modem commands such as a dial-up command, the AT Means Attention.

In addition, the RLP (Radio Link Protocol) interworking with the data service unit 52 is a type of a communication protocol for processing data from a reception and transmission terminal, that is, a Tx 60 and an Rx 61, from a wireless link, and retransmission. Provides a level of data quality to the upper tier (PPP). The Point-to-Point Protocol (PPP) 58 is a protocol that performs a function of maintaining a connection between an Interworking Function (IWF) and an N-WLL terminal, and includes TCP (55) and IP (56). It is widely used as an internet protocol and is responsible for the interface between a modem and an application located in the IWF.

3 is a flowchart illustrating a method for automatically storing MP3 files in a narrowband wireless subscriber network terminal according to the present invention.

First, it is determined whether the radio call processing between the terminal and the base station is a data service (S11).

As a result of the determination, if the wireless communication between the terminal and the base station is not a data service, general voice call processing is performed in step S12. If the data service is a data service, the address of the memory pool of the terminal is checked to freely store the memory pool. It is determined whether there is room (S13). Scanning the address of a memory pool implemented in SRAM or flash memory.

As a result of the determination in step S13, if there is no free storage capacity of the memory pool, in step S14, after deleting all the data stored in the memory pool, repeating step S11 to determine again whether the received call is a data service, If there is a free storage capacity, it is determined in step S15 whether the received data is a frame header of an MP3 file.

As a result of the determination in step S15, if the frame header of the MP3 file is not the same, after performing the general data service call processing in step S16, repeating step S13 of determining whether the storage capacity of the memory pool remains, and if the If the received data is the frame header of the MP3 file, the frame length and the cyclic redundancy check (CRC) are performed in step S17.

Subsequently, it is determined whether the frame length is checked in step S18, and if it is not confirmed, repeats step S16 of performing general data service call processing, and if the length of the frame is confirmed, repeats in step S19. It is determined whether the result of the redundancy check coincides with the length of the frame.

As a result of the determination in step S19, if the result of the cyclic redundancy check does not match the length of the frame, repeating step S16 of performing a general data service call processing, and if the result of the cyclic redundancy check is equal to the length of the frame If it matches, it is regarded as the correct MP3 file format and stored in the memory module (ie, memory pool) of the terminal (S20).

That is, when the frame header is detected, the frame length and the cyclic redundancy check (CRC) value can be known. Therefore, it is possible to verify whether the previously detected frame header with the frame length is the correct value. After verifying the frame length and comparing the cyclic redundancy check values, if the two values match, it is the correct MP3 file. Therefore, it is stored in the memory module of the terminal. Therefore, the terminal automatically scans, captures, and saves the MP3 file. It can be.

As described above, the method for automatically storing MP3 files of the narrowband wireless subscriber network terminal of the present invention can be performed by a user without using an external device such as a UART port or updating a MP3 file by replacing a memory module. Has the effect of automatically capturing and storing MP3s in the memory module.

Claims (1)

A narrowband wireless subscriber network terminal, A first step of determining whether the radio call processing between the terminal and the base station is a data service; As a result of the determination, if the wireless communication between the terminal and the base station is not a data service, general voice call processing is performed. If the data service is a data service, the storage capacity of the memory pool remains by checking the address of the memory pool of the terminal. Determining whether there is a second step; As a result of the determination in the second step, if there is no free storage capacity of the memory pool, after deleting all the data stored in the memory pool, it is determined whether the received call is a data service, and if there is free storage capacity of the memory pool, Determining whether the received data is a frame header of an MP3 file; As a result of the determination in the third step, if it is not the frame header of the MP3 file, the general data service is performed again to determine whether the storage capacity of the memory pool remains, and if the received data is the frame header of the MP3 file, A fourth step of performing a frame length and cyclic redundancy check (CRC); A fifth step of determining whether the length of the frame is checked; if not, performing general data service; and if the length of the frame is confirmed, determining whether a result of the cyclic redundancy check matches the length of the frame Wow; As a result of the determination in the fifth step, if the result of the cyclic redundancy check does not match the length of the frame, general data service is performed. If the result of the cyclic redundancy check matches the length of the frame, the correct MP3 file format is performed. And a sixth step of storing the memory module in a memory module of the terminal.