GB2347827A

GB2347827A - Testing a base station of a DECT system

Info

Publication number: GB2347827A
Application number: GB9930753A
Authority: GB
Inventors: Dong-Soo Jung; Jong-Boo Park
Original assignee: LG Information and Communications Ltd
Current assignee: LG Electronics Inc
Priority date: 1998-12-30
Filing date: 1999-12-29
Publication date: 2000-09-13
Anticipated expiration: 2019-12-29
Also published as: KR100553808B1; GB9930753D0; GB2347827B; KR20000045810A

Abstract

An arrangement for testing a base station of a DECT system in which a test signal is transmitted in a data slot to the base station from the main system. The base station extracts the transmitted test signal and retransmits it to the main system. The main system compares the transmitted and received test signals to determine if the base station is functioning correctly.

Description

APPARATS AND METHOD FOR TESTING BASE STATION OF DECT SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DECT (digital Enhanced cordless telecommunication), and more particularly, to an apparatus for testing a base station of a DECT system and to its method.

2. Description of the Background Art Figure 1 shows a general DECT system which inclues a base station 2, a fixed part connected to a main system 1 through a wire 3, and a wireless handset 4, a portable part performing a communication wirelessly through the base station 2.

As to the DECT system, in order to identify whether each base station installed in many places is normally operated, an installer should move to each place in person where the base station is installed to perform the communication.

Thus, this method has a problem in that it requires many people and much time.

Meanwhile, as another one, there is a method of using a loop back function of a line driver (not shown) provided in a wired connection part of the main system 1 and the base station 2.

That is, when a signal is transmitted from the main system 1 through its line driver to the base station 2, the line driver of the base station 2 that received the signal returns the signal to the main system 1.

And then, the signal fedback from the main system 1 is analyzed, thereby identifying the operation state of the base station 2.

However, this method is disadvantageous in an aspect that it only identifies the state of wire 3 between the main system and the base station 2, without capability of identifying whether internal blocks of the base station 2 are normally operated or not.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an apparatus for testing a base station of a DECT system in which a test signal is transmitted as being carried on a signal message that is received and transmitted between system and a base station and analyzed by the system, thereby identifying a state of the base station, and its method.

In addition, in the present invention, an RSSI (Received Signal Strength Indicator) signal is analyzed to identify an operation state of an RF module.

To achieve these and other advantages and in accordance with the , purpose of the present invention, as embodied and broadly described herein, there is provided an apparatus for testing a base station of a DECT system including : a main system logic unit consisting of a first encoder for inserting a predetermined transmission test signal into a transmission data slot and transmitting it to a base station and a first decoder extracting a receiving test signal from a receiving data slot received from the base station ; a test control unit for generating a transmission test signal to transmit it to the first encoder, comparing the receiving test signal inputted from the first encoder and the transmission test signal to judge the operation state of the base station, and outputting its result ; a base station logic unit consisting of a second decoder for extracting a test signal from the transmission data slot transmitted from the main system logic unit and a second encoder for inserting the test signal into the receiving data slot and transmitting it to the main system logic unit.

In order to attain the above object, there is also provided a method for testing a base station of DECT system including the steps of: inserting a predetermined transmission test signal into a transmission data slot by the main system and transmitting it to a base station; extracting a test signal from the transmission data slot inputted from the main system; inserting the test signal into a receiving data slot and transmitting it to the main system; comparing the transmission test signal and the receiving test signal inputted from the base station ; judging whether the base station is normally operated according to the comparison result ; and outputting the judged result as a predetermined signal.

Also, in order to attain the above object, the test control unit identifies an RSSI value transmitted from the base station so as to judge a state of a wireless part of the base station.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principes of the invention.

In the drawings: Figure 1 is a schematic view of a structure of a general DECT system in accordance with a conventional art; Figures 2A to 2D show signal message forms in use for the DECT system in accordance with the conventional art; Figures 3A and 3B show signal message forms for testing a base station of a DECT system in accordance with the present invention ; Figure 4 is a schematic block diagram of an internal construction of a WTIB (Wireless Terminal Interface Board, which interfaces a system and DECT Base Station) of a DECT system in accordance with the present invention; Figure 5 is a schematic block diagram of an internal construction of a base station of the DECT system in accordance with the present invention; Figure 6 is a detailed block diagram of an internal construction of a CPU of Figure 4 in accordance with the present invention; Figure 7 is a detailed block diagram of an internal construction of a the WTIB logic unit and a BS (Base Station) logic unit of Figures 4 and 5 in accordance with the present invention; and Figure 8 is a flow chart of operation of the base station of the DECT system in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

First, in view of explanation of a signal arrangement structure of the present invention, signal forms used for a general DECT system are illustrated in Figures 2A to 2D.

As shown in Figure 2A, a signal frame of the DECT system is made the basis of 10ms, which is divided into 24 slots. First 12 number of slots are used for transmission (TX) and the second 12 number of slots are used for receiving (RX).

Each slot is made by 480 bit, and more specifically, as shown in Figure 2B, including a synchronization region S of 32 bit for synchronizing, a data region D of 388 bit carrying a control and a data signal, an error correction region Z of 4 bit for correcting an error, and a guard band G of 56 bit for discriminating from the next slot.

The guard band G includes wireless control information, of which detailed structure is as shown in Figures 2C and 2D.

Figure 2C shows an arrangement structure of a signal transmitted from the main system to the base station, and Figure 2D shows an arrangement structure of a signal transmitted from the base station to the main system.

As shown in Figure 2C, the signal transmitted from the main system to the base station includes a 16 bit synchronization region Sync for synchronizing; 4 bit wireless control information region having a 1bit region (PO/P32) for indicating whether the current slot is a dummy bearer or a traffic bearer, a 1bit region (Tx/Rx) for indicating whether the current slot is for transmission use or for receiving use, a 1 bit region (Idle/Act) for indicating whether the current slot is in use or in an empty state and a 1 bit region (Ant Sw) used for diversity of a base station antenna; 4 bit frequency select region (frequency carrier) for selecting one of 10 frequency carriers; and 32 bit region that is empty.

The base station controls the wireless part (RF module) according to the control information, periodically scans the RSSI value of each slot, expresses its result as 4 bit data, and transmits a signal having the structure as shown in Figure 2B to the main system.

In the present invention, the 32 bit empty region in the signal structure as shown in Figures 2C and 2D is used for transmitting and receiving a test signal for testing an operation state of the base station. Figures 3A and 3B show the signal structure accordingly.

As shown in Figures 3A and 3B, the main system inserts 16 bit (1 word) test signal into the 32 bit empty region and transmits it to the base station. And then the main system receives a signal (Figure 3B) loop-back from the base station, and compares the two signals to thereby identify the operation state of the base station.

Figures 4 and 5 are schematic block diagrams of the main system and the base station of the DECT system performing the above operation.

Figure 4 is a schematic block diagram of an internal construction of a WT ! B of DECT interface processing board in accordance with the present invention, which includes a line driver 100 for wired connection interfacing with the base station; a WTIB logic unit 200 having an encoder 210 and decoder 200 for inserting into and extracting from various control information including a test signal in a transmitted/received voice data; a data processing unit 300 for processing a PCM data; a CPU 400 for generating a test signal, transmitting it to the base station, comparing it with a test signal fedback from the base station to thereby judge whether the base station is normally operated or not; and PC 500 as a user interface unit for enabling a test mode or displaying the test result.

Figure 5 is a schematic block diagram of an internal construction of a base station of the DECT system in accordance with the present invention, which inclues a line driver 600 for performing a wire interface with a WTIB ; a BS logic unit 700 having an encoder 700 and a decoder 710 for inserting into and extracting from various control signal including a voice data inputted through an antenna and a test signal for transmitting to and receiving from the WTIB ; and an RF module 800 for processing a wireless data, measuring an RSSI value and transmitting it to the logic unit 700.

Figure 6 is a detailed block diagram of an internal construction of a CPU of Figure 4 in accordance with the present invention.

As shown in the drawing, the CPU 400 includes a user interface unit 401 for providing an interface for receiving a test enable signal from a user and informing the user of a result of testing; a control unit 402 for controlling each block that performs a testing mode when a test enable signal (test enable) is applied; a comparing unit 403 for comparing transmission test signal (Tx test) and a receiving test signal (test) under the control of the control unit 402; an error judging unit 404 for counting the number of errors according to the comparison result of the comparing unit to judge whether there is an error; a test signal generating unit 405 for generating an arbitrary test signal of 16 bit (1 word) under the control of the control unit 401; a data input/output unit 406 for inputting and outputting data that is transmitted to or received from the base station logic unit 200; a Tx register 407 for temporarily storing the transmitted test signal ; and an Rx register 408 for temporarily storing the received test signal.

Figure 7 is a detailed block diagram of an internal construction of a the WTIB logic unit and a BS logic unit of Figures 4 and 5 in accordance with the present invention.

As shown the drawing, the encoder 210 of the WTIB logic unit 200 includes a buffer 212 for temporarily storing the transmission signal (Tx test) applied from the CPU 400, a test control unit 211 for controlling the buffer 212 according to the test enable signal (test enable) ; a multiplexer 213 for multiplexing the data (S+D field) and wireless control information (S~data) inputted from the data processing unit 300 and the test signal (Tx test) inputted from the buffer 212 ; and a synchronization unit 214 for providing a synchronous signal to the multiplexer 213.

The decoder 710 of the BS logic unit 700 includes a demultiplexer 711 for receiving a signal outputted from the encoder 210 of the WTIB logic unit 200 through the line interface and separating it to wireless control information, a data signal and a test signal ; a synchronization unit 712 for providing a synchronous signal to the demultiplexer 711; and an RF control signal generation unit 713 for generating a wireless control signal for controlling the RF module 800 from the wireless control information by the demultiplexer 711.

The encoder 720 of the BS logic unit 700 includes a buffer 721 for storing the test signal inputted from the demultiplexer of the decoder 710 for a predetermined time; a multiplexer 722 for multiplexing the data signal (S+D field) and the RSSI signal (RSSI) from the RF module 800 and the signal inputted from the buffer 721; and a synchronization unit 723 for providing a synchronous signal to the multiplexer 722.

The decoder 220 of the WTIB logic unit 200 includes a demultiplexer 221 for receiving a signal outputted from the encoder 720 of the BS logic unit 720 through the line interface and demultiplexing it to a test signal (test), a data signal (S+D field) and an RSSI signal (RSSI) ; and a synchronization unit 222 for providing a synchronous signal to the demultiplexer 221.

Figure 8 is a flow chart of operation of the base station of the DECT system in accordance with the present invention.

The testing process for the base station of the DECT system of the present invention constructed as described will now be explained with reference to Figure 8.

First, when a key for performing a testing mode is inputted by the user, the user interface unit 401 of the CPU 400 applies the test enable signal (test enable) to the control unit 402 in a step S1.

Then, the control unit 402 controls the test signal generation unit 405 so that it generates an arbitrary test signal (Tx test).

At this time, as shown in Figure 3, the test signal generation unit 405 generates an arbitrary signal of 16 bit (1 word) to be inserted to the test region (test) of each guard band G of the 12 transmission slots, and stores it in the Tx register 407 in a step S2.

And, the transmission test signal (Tx test} is applied to the encoder 210 of the WTIB logic unit 200 through the data input/output unit 406 under the control of the control unit 402 and stored in the buffer 212 temporarily.

When the test enable signal (test-enable) is applied from the CPU 400, the test control unit 211 of the encoder 210 controls the buffer 212 and outputs the stored transmission test signal (Tx test) to the multiplexer 213.

Then, the multiplexer 213 multiplexes the data signal (S+D field) and the wireless control information (S data) inputted from the data processing unit 300 and the test signal inputted from the buffer 212 and outputs it in a step S3.

At this time, the synchronization unit 214 detects a synchronous signal (Sync) of the wireless control information (S~data) and provides it to the multiplexer 213 so that the test signal is inserted into the test region (test) of the guard band G.

Accordingly, the multiplexer 213 inserts the data signal (S+D field), the wireless control information (S data) and the test signal (Tx test) into its proper position, so as to be outputted.

The transmission data frame with the test signal inserted is transmitted to the base station by wire through the line driver 100 in a step S4.

Meanwhile, the transmission data frame inputted through the line driver 600 of the base station is applied to the decoder 710 of the BS logic unit 700.

Then, the demultiplexer 711 of the decoder 710 demultiplexes the received transmission data frame to the wireless control information (S data), the data signal (S+D field) and the test signal (Tx test) according to the synchronous signal of the synchronization unit 712, and outputs it respectively in a step 5.

The wireless control information (S data) is inputted to the RF control signal generation unit 713, according to which various wireless control signals are generated for controlling the RF module 800, and the data signal (S+D field) is transmitted through the RF module 800 wirelessly. The test signal (Tx test) is applied to the encoder 720 of the BS logic unit.

Then, the test signal is delayed for a predetermined time, for example 5ms where the data frame begins from, by the buffer 721 of the encoder 720 and then inputted to the multiplexer 722.

The multiplexer 722 multiplexes the data signal (S+D field) and the RSSI signal (RSSI) applied from the RF module 800 and the test signal inputted from the buffer 721, and outputs it in a step S6.

At this time, the synchronization unit 723 detects a synchronous signal of the data signal (S+D field) inputted from the RF module 800 and provides the synchronous signal (S field) to the multiplexer 722.

In that manner, the data frame including the test signal is inputted to the WTIB of the main system and inputted to the decoder 220 of the WTIB logic unit 200 through the line driver 100.

Then, the demultiplexer 221 of the decoder 220 demultiplexes the received data frame to the test signal (Rx~test), the data signal (S+D field) and the RSSI signal (RSSI), and outputs it to the CPU 400 and the data processing unit 300, respectively, in a step S8.

At this time, the synchronization unit 222 detects a synchronization signal (Sync) of the wireless control information (S data) among the signals applied from the encoder 720 of the BS logic unit 700 and provides the synchronization signal to the demultiplexer 221.

The control unit 402 of the CPU 400 sequentially stores the receiving test signal (Rx test) inputted from the decoder 220 of the WTIB logic unit 200 in the Rx register 408 and controls the comparing unit 403 so that the comparing unit 403 compares the transmission test signal (Tx test) stored in the Tx register 407 and the receiving test signal (Rx~test).

Accordingly, the comparing unit 403 compares the transmission test signal (Tx test) and the receiving test signal (Rx test) one slot by one slot, and if the two signals are different to each other, it increases the number of the counting at the error counter 404 in a step S9.

After a predetermined time, the control unit 402 recognizes the count value of the error counter 404 and judges whether there is an error in the base station in a step S10.

There are possibly various error judging methods, and in the present invention, the method is taken in that a predetermined threshold value is set, and in case that the counted value goes beyond the threshold value, it is judged that there is an error in the base station, which is outputted as a predetermined signal and displayed on the PC 500 through the user interface unit 401 for user's notification.

Through the above-described process, it is identified whether the BS logic unit 700 of the base station is normally operated or not, and it is also possible to judge whether the RF module of the base station is normally operated. Thus, the error part of the current base station can be easily identified.

In other words, following the step S9, the control unit 401 controls in a manner that in case that the error count value is greater than a predetermined threshold value, a predetermined signal indicating that the logic unit 700 of the base station has an error is outputted, while in case that the count value is smaller than the threshold value, the RSSI value inputted from the base station is identified.

The RSSI value is changed at predetermined time intervals during a normal operation, i. e., at every 20 seconds in the system of the present invention.

< By using this fact, in case that there is no change in the RSSI value or in case that the values are all'0', the control unit 402 outputs a predetermined signal indicating that the RF module 800 of the base station has an error.

Accordingly, the user can easily identifies the error in operation of the logic unit or the RF module 800 of the base station according to the different warning sound or the LED.

Though various blocks for testing the operation of the base station are implemented in the existing CPU 400 in the present invention, the blocks may be implemented in the logic unit 200 if there is no room for the CPU 400.

And, with respect to outputting the test result, it may be outputted through a monitor of the PC, or a predetermined warning sounds that are different, or ON/OFF operation of the LED can be used so that a system manager can easily identify an error.

In addition, referring to the generation of the test signal, besides the method for generating an arbitrary test signal of 16 bit and inserting it into each slot, a predetermined test signal may be pre-set for user, and the size and interval of the test signal can be varied suitably to an environment of each system.

As so far described, the apparatus and method for testing the base station of the DECT system of the present invention has advantages in that the system can easily identify whether each base station is normally operated, so that maintenance of the system is quite easy.

As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalence of such meets and bounds are therefore intended to be embraced by the appended claims.

Claims

What is claimed is:

1. An apparatus for testing a base station of a DECT system including : a main system logic unit consisting of a first encoder for inserting a predetermined transmission test signal into a transmission data slot and transmitting it to a base station and a first decoder extracting a receiving test signal from a receiving data slot received from the base station; a test control unit for generating a transmission test signal to transmit it to the first encoder, comparing the receiving test signal inputted from the first " decoder and the transmission test signal to judge the operation state of the base station, and outputting its result ; a base station logic unit consisting of a second decoder for extracting a test signal from the transmission data slot transmitted from the main system logic unit and a second decoder for inserting the test signal into the receiving data slot and transmitting it to the main system logic unit.

2. The apparatus according to claim 1, wherein the first encoder inclues : a buffer for temporarily storing the transmission signal ; a buffer control unit for controlling the buffer according to the test enable signal and outputting a transmission test signal ; a multiplexer for multiplexing the data and wireless control information, and the test signal inputted from the buffer ; and a synchronization unit for providing a synchronous signal to the multiplexer.

3. The apparatus according to claim 1, wherein the first decoder includes ; a demultiplexer for receiving a signal outputted from the base station logic unit through the line interface and separating it to a test signal, a data signal and an RSSI signal ; and a synchronization unit for providing a synchronous signal to the demultiplexer.

4. The apparatus according to claim 1, wherein the second encoder includes : a buffer for storing the test signal inputted from the second decoder for a predetermined time; a multiplexer for multiplexing the test signal inputted from the buffer, the data signal and the RSSI signal inputted from the RF module; and a synchronization unit for providing a synchronous signal to the multiplexer.

5. The apparatus according to claim 1, wherein the second decoder includes : a demultiplexer for receiving a signal outputted from the main system logic unit through the line interface and demultiplexing it wireless control information, a data signal and a test signal ; a synchronization unit for providing a synchronous signal to the demultiplexer, and an RF control signal generation unit for generating a wireless control signal to control the RF module from the wireless control information outputted from the demultiplexer.

6. The apparatus according to claim 1, wherein the test control unit comprising: a test signal generating unit for generating a predetermined transmission test signal according to a test enable signal ; a transmission register for storing the transmission test signal ; a receiving register for storing a receiving test signal applied from the base station; a comparing unit for comparing the transmission test signal and the receiving test signal ; a judging unit for judging an operation state of the base station according to the comparison result ; and a user interface unit for receiving the test enable signal from the user or outputting the judged result of the judging unit as a predetermined signal for the user's notification.

7. The apparatus according to claim 6, wherein the judging unit inclues a function of identifying an RSSI value transmitted from the base station and judging the state of a wireless part of the base station.

8. The apparatus according to claim 1, wherein the predetermined transmission test signal is inserted in to a guard band of the transmission data slot transmitted from the main system to the base station;

9. The apparatus according to claim 8, wherein the predetermined test signal is an arbitrary signal of 16 bit.

10. The apparatus according to claim 1, wherein the receiving test signal is inserted into the guard band of the receiving data slot transmitted from the base station to the main system.

11. A method for testing a base station of DECT system comprising : a first step of inserting a predetermined transmission test signal into a transmission data slot by the main system and transmitting it to a base station; a second step of extracting a test signal from the transmission data slot inputted from the main system ; a third step of inserting the test signal into a receiving data slot and transmitting it to the main system; a fourth step of comparing the transmission test signal and the receiving test signal inputted from the base station; and a fifth step of judging whether the base station is normally operated according to the comparison result ; and outputting the judged result as a predetermined signal.

12. The method according to claim 11, wherein in the fifth step in case that the transmission test signal and the receiving test signal are different to each other according to the result of the fourth step, the error count number is increased one by one, and in case that the error count number is greater than a predetermined threshold value, it is judged that there is an error in the base station.

13. The method according to claim 11, wherein the fifth step includes a sub-step of identifying an RSSI value transmitted from the base station and judging a state of the wireless part of the base station.

14. The method according to claim 11, wherein the predetermined transmission test signal is inserted into a guard band of a transmission data slot transmitted from the main system to the base station.

15. The method according to claim 14, wherein the predetermined test signal is an arbitrary signal of 16 bit.

16. The method according to claim 11, wherein the receiving test signal is inserted into the guard band of the receiving data slot transmitted from the base station to the main system.

17. The method according to claim 11, wherein in the sixth step the judged result is expressed as a predetermined warning sound or ON/OFF of an LED.