JPH08275236A - Mobile communication system - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a mobile communication system in which the processing speed required for displaying information in page units on a mobile terminal can be apparently made constant while keeping the communication quality constant. In a mobile communication system in which information is transmitted between a base station 1 and a mobile station 3 via a high speed downlink 4 and a low speed uplink 5, the base station 1 is managed in page units and page numbers are assigned to each page. In response to a browsing request from the terminal 3, the information with is transmitted at a variable transmission rate via the high-speed downlink 4, and the terminal 3 sends the page number to the base station 3 at a low speed in response to the user's browsing instruction input. Information transmitted from the base station 1 via the high speed downlink 4 when the transmission speed of the high speed downlink 4 is equal to or lower than a predetermined value is stored in a memory and stored in a memory to obtain information on a desired page. Is displayed, and the page numbers of the previous and next pages are transmitted as a browsing request to the base station 1 during the display, and the information of the previous and next pages is stored in the memory.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system, and more particularly to a transmission / reception asymmetric communication system having a high speed downlink and a low speed uplink.

[0002]

2. Description of the Related Art In a mobile communication system, not only a mobile terminal communicates with a remote place, but also a mobile terminal accesses a database on a network to browse information stored in a database. Attempts are being made. In such a system, high speed communication is required. Since a large amount of power is consumed to perform high speed communication, it has been considered difficult to perform high speed communication with a portable mobile terminal powered by a battery. For such a problem, from the viewpoint that the reception does not consume much power compared to the transmission, the transmission from the mobile terminal to the base station is performed at a low speed, and the reception from the base station is performed at a high speed. As such, a so-called transmission / reception asymmetric communication system for increasing the communication speed is considered.

By the way, in such a mobile communication system, the transmission quality may change as the terminal moves. A variable transmission rate method and an error retransmission control method are known as methods for performing communication while maintaining a constant communication quality against changes in transmission quality. The variable transmission rate system guarantees the communication quality by lowering the transmission rate when the transmission quality is poor and increasing the transmission rate when the transmission quality is good. In this method, the transmission rate changes depending on the transmission quality, so the transmission time per packet differs for each packet. The error retransmission control method guarantees quality by retransmitting an erroneous packet.
In this method, erroneous packets are transmitted multiple times, so
Again, the transmission time per packet differs for each packet.

As described above, in the variable transmission rate system and the error retransmission control system, the transmission time per packet changes variously. For this reason, when the information from the database is browsed in the mobile terminal, the waiting time required to display the necessary information may change variously as the transmission time changes. For example, when the information stored in the database is managed in page units and information is retrieved and displayed page by page as if you were reading a book on a mobile terminal, there is almost no waiting time to display a page. It sometimes takes a long time to display a certain page. This is not preferable for the user of the mobile terminal in terms of operability.

To solve this problem, the mobile terminal is provided with a large-capacity memory so that the terminal user receives all the information of the page which is considered to be necessary, stores it in the memory, and reads it out at any time. do it. However, in particular, the memory built in a portable mobile terminal is naturally limited in its storage capacity from the viewpoints of small size and light weight and power consumption, and only a few pages of information can be stored at most. Displaying the information from will still take some time to retrieve a page that is not stored in memory.

[0006]

As described above, in the conventional mobile communication system, if the communication quality between the mobile terminal and the base station is kept constant by the variable transmission rate method or the error retransmission control method, the transmission is performed. Since the time changes variously, for example, when utilizing the information managed in page units in the database in the terminal, the time required for display varies depending on the page, and there is a problem that operability is poor for the user of the terminal.

[0007] The present invention provides a mobile communication system which has an excellent operability because the processing speed required for displaying information in page units on a portable mobile terminal can be made apparently constant while keeping the communication quality constant. To aim.

[0008]

In order to solve the above-mentioned problems, the first invention comprises a base station and a mobile terminal, which transmits information from the base station to the mobile station via a high speed downlink. In a mobile communication system that transmits information to a base station via a low speed uplink, which has a slower transmission speed than a high speed downlink, the base station stores information that is managed in page units and has a page number attached to each page. And means for transmitting the information accumulated by the accumulating means at a variable transmission rate via the high speed downlink in response to a browsing request from the mobile terminal.
On the other hand, the mobile terminal transmits a page number corresponding to a browsing instruction input by a user of the mobile terminal as a browsing request to the base station via a low-speed uplink, and a high-speed downlink transmission speed is predetermined. When the value is less than or equal to the value, the storage means stores and holds the information transmitted from the base station through the high-speed downlink, and the display means for displaying the information of the desired page read from the storage means. When the downlink transmission speed is less than or equal to a predetermined value, the browsing request transmission unit requests at least the page number of the page before or after the desired page while the information of the desired page is displayed on the display unit. Is transmitted to the base station, and the storage means fetches and stores at least the information of the previous or subsequent page.

Here, the storage means stores, for example, a first storage area for storing and holding information of a previous page of a page on which the display means is currently displaying information, and information of a page for which current information is being displayed. A storage area of the second storage to be held, a third storage area to store and hold the information of the next page of the page currently displaying the information, and a viewing instruction input of the previous page or the next page by the user of the mobile terminal The information stored and held in the first storage area or the third storage area is newly supplied to the display means as the information of the second storage area, and the information is stored in the third storage area or the first storage area. And a means for taking in information of the previous page or the next page transmitted from the base station.

According to the second aspect of the present invention, it is composed of a base station and a mobile terminal, transmits information from the base station to the mobile station via a high speed downlink, and the mobile terminal transmits the information to the base station from the high speed downlink at a low transmission speed. In a mobile communication system that transmits information via an uplink, a base station stores storage information that is managed in page units and that stores information with page numbers assigned to each page, and information stored by this storage means. Information transmitting means for transmitting via the high speed downlink in response to a browsing request from a mobile terminal and error retransmission for controlling the information transmitting means to retransmit the same information in response to an error retransmission request from the mobile terminal. And control means.
On the other hand, the mobile terminal transmits the page number corresponding to the browsing instruction input by the user of the mobile terminal as a browsing request to the base station via the low speed uplink, and the base station via the high speed downlink. Storage unit for storing and holding the information transmitted by the storage unit, the display unit for displaying the information of the desired page read from the storage unit, and the error of the information transmitted from the base station through the high-speed downlink. And an error resending request sending unit that sends an error resending request to the base station via the low speed uplink when detected, and at least the browsing request sending unit is provided while the information of the desired page is displayed on the display unit. The page number of the page before or after the desired page is transmitted to the base station as a browsing request, and the storage unit fetches at least the information of the page before or after the page. And to store it held in.

According to a third aspect of the present invention, a base station and a mobile terminal are used, information is transmitted from the base station to the mobile station via a high speed downlink, and the transmission speed is slower than the high speed downlink from the mobile terminal to the base station. In a mobile communication system that transmits information via an uplink, a base station stores storage information that is managed in page units and that stores information with page numbers assigned to each page, and information stored by this storage means. And an information transmitting unit for transmitting a plurality of pages in units of a plurality of pages via the high-speed downlink in response to a browsing request from the mobile terminal. On the other hand, the mobile terminal stores the information of a plurality of pages transmitted from the base station via the high-speed downlink, and stores the page, and the page corresponding to the browsing instruction input by the user of the mobile terminal. Display means for displaying the information of the page read from the storage means when the information of the page is stored, and the browsing instruction input when the information of the page corresponding to the input of the browsing instruction is not stored in the storage means And a browsing request transmission means for transmitting a browsing request according to the above to the base station via the low-speed uplink.

According to a fourth aspect of the present invention, a base station and a mobile terminal are provided, information is transmitted from the base station to the mobile station via a high speed downlink, and the transmission speed from the mobile terminal to the base station is lower than that of the high speed downlink. In a mobile communication system that transmits information via an uplink, a base station stores storage information that is managed in page units and that stores information with page numbers assigned to each page, and information stored by this storage means. And information transmission means for transmitting via a high speed downlink in response to a browsing request from a mobile terminal. on the other hand,
The mobile terminal transmits a page number corresponding to the browsing instruction input by the user of the mobile terminal as a browsing request to the base station via the low speed uplink, and the information transmitted from the base station via the high speed downlink. While storing and retaining the information of the desired page in the storage means, while the information of the desired page is displayed, at least the page number of the page before or after the desired page is transmitted to the base station as a browsing request. A first mode in which at least the previous or subsequent page information is captured and stored in the storage means, and a plurality of pages of information transmitted from the base station via the high-speed downlink are stored in the storage means, When information of a page corresponding to a viewing instruction input by the user of the mobile terminal is stored in the storage means, information of the page read from the storage means is stored. And a second mode for transmitting a browsing request corresponding to the browsing instruction input to the base station via the low-speed uplink when the information of the page corresponding to the browsing instruction input is not stored in the storage means. Have at least
It is characterized in that the first and second modes are selectable.

In the fifth invention, the base station transmits most of the information to be transmitted to the mobile terminal as a plurality of fixed length blocks on the high speed downlink, and transmits the rest of the information from the high speed downlink. It is characterized by transmitting over a slow, slow downlink.

In the sixth invention, the base station has means for transmitting attribute information corresponding to the information transmitted by the information transmitting means to the mobile terminal through the low speed downlink whose transmission speed is slower than that of the high speed downlink. Characterize.

[0015]

In the first aspect of the invention, while the user of the mobile terminal is browsing a certain page in the variable transmission rate system, the information of the previous page or the next page which is likely to be browsed by the user next is prefetched. Then, the communication for storing in the memory is performed between the mobile terminal and the base station. In this case, since the time required for communication is shorter than the time required for browsing information, even if the transmission speed is set low due to poor transmission quality, the user is kept waiting to browse the desired page. Without having to go back to the previous page, go to the next page, you can browse the information as if you were reading a book, and the operability is significantly improved. Further, when the transmission quality is good and the transmission speed is high, power consumption can be saved by not performing such buffering.

In the second invention, in the error retransmission control method, while the user of the mobile terminal is browsing a certain page, information of the previous page and the next page which is likely to be browsed by the user next is displayed. Communication for prefetching and storing in the memory is performed between the mobile terminal and the base station. In this case, since the time required for communication is shorter than the time required for browsing information, even if an error is detected and retransmission control is performed, the user does not have to wait when browsing a desired page. It is possible to browse information as if returning to the page or proceeding to the next page as if reading a book, and the operability is significantly improved. Further, when retransmission control is not performed, power consumption can be saved by not performing such buffering.

In the third aspect of the invention, the mobile terminal stores information of a plurality of pages transmitted from the base station in a cache memory or the like, and the information of the page requested to be browsed is not stored in the cache memory. Since communication is requested to the base station only at times, it is not necessary to perform communication between the terminal and the base station each time for a page that is frequently referred to, for example, a page describing a table of contents or an operating method. In this case also, the difference in transmission speed can be absorbed by the buffer. Furthermore, since the information is transmitted in a large unit, for example, several pages using the high speed downlink, it is possible to reduce the overhead in transmission.

According to the fourth invention, the first mode based on the first or second invention and the second mode based on the third invention are selected according to the mode of browsing the information desired by the user of the mobile terminal. Can be selected.

According to the fifth aspect of the invention, most of the information to be transmitted to the mobile terminal is transmitted as a plurality of fixed length blocks on the high speed downlink, and the remaining portion is transmitted via the low speed downlink, whereby the mobile terminal is moved. Information can be easily managed at the terminal, pages of variable length can be easily realized, and line usage efficiency is improved.

In the sixth invention, by utilizing the low speed downlink for transmitting the attribute information, it becomes possible to easily manage the information by the mobile terminal using the attribute information, and the variable length page is used. It is easy to realize and the usage efficiency of the line is improved.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a mobile communication system according to an embodiment of the present invention. As shown in the figure, within the service area (zone) 2 formed by the base station 1, the base station 1
A portable mobile terminal 3 that communicates with is located. Between the base station 1 and the mobile terminal 3, a high-speed downlink 4 for transmitting information from the base station 1 to the mobile terminal 3 is used as a wireless transmission path, and information is transmitted from the mobile terminal 3 to the base station 1. A low-speed uplink 5 is formed for this purpose. As will be described later, the low speed uplink 5 may be combined with the low speed downlink 6 to form a low speed bidirectional link.

A storage unit 7 and a network 8 are connected to the base station 1, and the base station 1 fetches appropriate information from a database 9 via the network 8 and stores it in the storage unit 7. The information 10 stored in the database 9 is managed in page units as shown in FIG. 3, and each page is given a page number. Database 9
May be held by the base station 1.

The mobile terminal 3 transmits a page number indicating a page of information to be browsed (displayed) among the information stored in the database 9 to the base station 1 via the low speed uplink 5 as a browse request. Upon receiving this browsing request, the base station 1 fetches the page information of the requested page number from the database 9 into the storage unit 7 via the network 8 and transmits it to the mobile terminal 3 via the high speed downlink 4. To do. At this time, there is no restriction on the page number requested by the mobile terminal 3 as a browsing request, and an arbitrary page number desired by the user of the terminal 3 can be requested. Therefore, the mobile terminal 3 can pre-read the information of the page that is likely to be browsed by the user next, and store it in the main memory 15 or the cache memory 19, for example, as described later. .

FIG. 2 shows a configuration example of the mobile terminal 3. As shown in the figure, the mobile terminal 3 includes an antenna 11, a variable transmission rate transmission / reception device 12, an input unit 13, a CPU 14,
A main memory 15, a display unit 16, a DMA (direct memory access) controller 17, a cache controller 18, and a cache memory 19 are connected by a bus 20. The function of each unit will be described later.

The variable transmission rate transmission / reception device 12 maintains a constant transmission quality by lowering the transmission rate when the transmission quality of the high speed downlink 4 and the low speed uplink 5 is poor and increasing the transmission rate when the transmission quality is good. It is provided for the purpose of keeping. In addition, since the effect of buffering is low when the transmission speed is high, buffering is performed only when the transmission speed is low, and when not buffering, unnecessary memory is not supplied, thus saving the battery of the power supply. .

The variable transmission rate transmission / reception device 12 has a radio circuit section 21 including a transmission / reception circuit, a transmission signal source 22, a programmable filter 23, and a demodulator 2 as shown in FIG.
4, a clock generator 25, a transmission quality estimation unit 26, and a control unit 27. The wireless circuit unit 21 converts an RF signal received by the antenna 11 from the base station 1 into an IF signal or a baseband signal. This wireless circuit section 21
The output signal of 1 is band-limited by the programmable filter 23 including a low-pass filter, and then converted into a digital signal (bit string) by the demodulator 24. The bandwidth of the digital signal handled by the demodulator 24 is the clock generator 2
It is controlled by a clock signal generated by the signal generator 5.

The transmission quality estimating section 26 outputs an estimated value of the transmission quality by measuring a physical phenomenon having a high correlation with the transmission quality. For example, the relation between the phenomenon value of the physical phenomenon and the estimated value is stored in the ROM. It is realized by the table lookup described in the above. Although the transmission rate changes depending on the transmission quality, it is not only difficult to measure the transmission quality itself, such as when the hardware becomes large-scale and the power consumption increases, but it is difficult to measure the transmission quality in the first place. Therefore, it is desirable to substitute for the measurement of the physical phenomenon that is highly correlated with the transmission quality. Such a physical phenomenon may be, for example, an electric field strength, an eye pattern spread, a measured value of a transmission line error rate by measuring a known pattern, an output of an error correction unit, or the like, or a combination thereof. In the example of FIG. 4, the transmission quality estimation unit 26 uses the wireless circuit 2
The transmission quality is estimated from the received output signal of 1.

Based on the estimated value of the transmission quality estimation unit 26, the control unit 27 sends a signal designating the transmission rate to the transmission signal source 2
2 to the wireless circuit section 21. Wireless circuit unit 21
Transmits this transmission speed designation signal from the antenna 11 to the base station 1 via the low speed uplink 5. Upon receiving this transmission rate designation signal, the base station 1 transmits information via the downlink 4 at the designated transmission rate. That is,
When the transmission quality estimation unit 26 estimates that the transmission quality is poor, the base station 1 operates to reduce the transmission rate.

The control unit 27 controls the cycle of the clock generated by the clock generator 25 in accordance with the change of the transmission rate from the base station 1 to realize the variable transmission rate at the time of reception and the programmable filter 23. It also controls the characteristics of. The characteristic control of the latter programmable filter 23 is
This is performed in order to improve the performance in consideration that the band of noise to be removed also changes due to the change of the transmission rate.

The bit string output from the demodulator 24 shown in FIG. 4 is sent to the main memory 15 by the CPU 14 in FIG. 2 or directly via the DMA controller 17, or to the cache memory 1 via the cache controller 18.
9 is written. The information written in the main memory 15 or the cache memory 19 is displayed on the display unit 16. As the display unit 16, for example, a liquid crystal display suitable for the portable mobile terminal 3 is used. The bit string may not be stored in the main memory 15 and may be stored in the video RAM (not shown) using the DMA controller 17.

The main memory 15 or the cache memory 19 is a CPU based on the transmission rate information from the control unit 27 in FIG.
14 or the cache controller 18, and operates to buffer the information transmitted from the base station 1 only when the transmission rate is less than or equal to a predetermined value.

FIG. 5 shows the information (bit string output from the demodulator 24) thus transmitted from the base station 1.
FIG. 3 is a diagram showing the configuration of a storage area in the main memory 15 or the cache memory 19 for buffering the data. In this example, it comprises a memory (A) 31, a memory (B) 32, a memory (C) 33 and a selector 34. The selector 34 is
A control signal is received from the CPU 14 via a control line connected to the bus 20, and writing (writing) and reading (reading) of the memories 31, 32 and 33 are independently selected. That is, since the memories 31, 32, and 33 are managed independently, it is possible to read and write at the same time even if they have the same address as long as they are different memories. Therefore, two address lines for the selector 34 are prepared, one for reading and the other for writing. Further, the selector 34 also has a function of switching the memories 31, 32 and 33 by a control signal supplied via a control line.

By configuring the main memory 15 or the cache memory 19 in this way, the memory 3
Information from the base station 1 can be written in any one of 1, 32, and 33, and the written information can be read out from any other one and displayed on the display unit 16.

FIG. 6 shows a memory (A) by the selector 34.
It is a figure which shows the mode of switching of 31, memory (B) 32, and memory (C) 33, t is the time which is currently displaying on the display part 16, t-1 shows the state one hour before. There is. The memory A is used to hold the information of the currently displayed page-1 (previous page), the memory B is used to hold the information of the currently displayed page,
The memory C is used to hold information on the currently displayed page + 1 (next page).

The user of the mobile terminal 3 selects the input unit 13
When a "next page instruction", that is, an instruction to display the next page is input, the contents of the memory A are discarded, and instead, the contents of the memory B at time t-1 are copied to the memory A, and at time t- The contents of the memory C in 1 are copied to the memory B, and the contents of the memory B are displayed on the display unit 16. Here, at time t, the content of the memory C is not the information of the displayed page + 1 (next page), so the content of the memory B is transmitted from the base station 1 while the user is browsing. The information of the next page to be fetched is stored in the memory C.

Similarly, when the user of the mobile terminal 3 inputs a "previous page instruction", that is, an instruction to display the previous page, from the input unit 13, the contents of the memory B are stored in the memory C.
The contents of the memory A are respectively copied to the memory B, the contents of the memory B are displayed on the display unit 16, and
The information of the page two pages before, which is transmitted from the base station 1, is newly read as the information of the previous page.

Although copying is performed here, the above-described function can be realized by incorporating a selection circuit in the selector 34 and omitting the operation of copying and simply switching.

Next, the page structure of the information stored in the database 9 will be described. The page structure is advantageous in that it has a fixed length from the viewpoint of management, and that a change in transmission rate can be absorbed by a memory (buffer).

FIG. 7 shows an example of a fixed-length page structure, in which a padding (padding) is added after the variable-length information section.
Aligned to a fixed length by arranging.

FIG. 8 is another example of a fixed-length page structure, in which the information section is composed of n blocks 1 to n, blocks 1 to n-1 are fixed-length blocks, and the final block n is variable. As a long block, padding is arranged after the final block n to make the entire length a fixed length.

FIG. 9 shows another example of the page structure, in which the information section is composed of n blocks 1 to n, and blocks 1 to
The block n-1 is a fixed-length block, and the final block n
Is the same as that of FIG. 8 except that padding is not arranged and the entire block has a variable length. However, in this example, fixed length blocks 1 to n-1
Is transmitted via the high speed downlink 4, and the final block n which is a variable length block is transmitted via the low speed downlink 6. That is, most of the information on the page is transmitted through the high-speed downlink 4 in a relatively large fixed-length block, and the remaining small amount of information is transmitted as a variable-length block through the low-speed downlink 6. The change can be absorbed in the memory (buffer), and the usage efficiency of the line is improved.

Further, in the page structure shown in FIG.
The information transmitted in the variable-length block n may be attribute information added to the page information instead of the page information. As such attribute information, for example, a table of contents, a value indicating the amount of information on a page, information indicating the presence or absence of a figure or image in the page, and other information can be considered.

FIG. 10 shows still another example of the page structure, in which the information part is composed of a plurality of fixed length frames 1 to n, and padding is arranged at the final part to make the whole fixed length. In this case, each frame 1 to n is error detection coded so that ARQ (automatic retransmission request) can be performed. The system configuration when the page configuration of FIG. 10 is used will be described later.

In this embodiment, the input section 13 is provided with a mode switching function so that at least two modes can be switched. Hereinafter, these modes will be described.

<First Mode> In this mode, the page number of the page to be browsed from the mobile terminal 3 is transmitted to the base station 1 via the low-speed uplink 5 as a browsing request. Upon receiving the page number of the browse request, the base station 1 fetches the information of the corresponding page from the database 9 into the storage unit 7 via the network 9 and transmits it to the mobile terminal 3 via the high speed downlink 4. Then, the mobile terminal 3 continues to transmit the page numbers of the pages before and after the page for which the browsing request is first made to the base station 1 in the same manner, and the base station 1 sequentially outputs the page information of those page numbers in the same manner as above. It is transmitted to the mobile terminal 3.

In the mobile terminal 3, when the transmission rate is less than or equal to the predetermined value, the information transmitted from the base station 1 in this way is stored in the main memory 1 as described with reference to FIGS.
5 or write buffering in the cache memory 19. In this case, the mobile terminal 3 can immediately display the pages before and after the page currently displayed and viewed on the display unit 16 by instructing the previous page and the next page. That is, the user of the mobile terminal 3 can browse the information 10 stored in the database 9 as if reading a book, such as returning from the currently browsed page to the previous page or to the next page. .

<Second Mode> In this mode, the page number which is the browsing request from the mobile terminal 3 is temporarily trapped in the cache controller 18. The cache controller 18 checks whether the page information of the page number of the browse request is stored in the cache memory 19 and, if the information of the corresponding page is stored, transfers it to the display unit 16, but it is stored. If not, a transmission request is transmitted to the effect that the page having the page number of the browsing request includes information. This transmission request is transmitted from the mobile terminal 3 to the base station 1 via the low-speed uplink 5 to the base station 1. In response to this request, the base station 1 transmits the information on the relevant page to the mobile terminal 3.

According to another aspect, the browsing request from the mobile terminal 3 is made to the DMA controller 17 in block units in the second transmission mode. DMA controller 1
Reference numeral 7 checks whether the information of the page of the page number requested to be browsed is stored in the cache memory 19 and, if the information of the relevant page is stored, transfers it to the display unit 16, but the information is stored. If not, a transmission request is transmitted to the effect that the page having the page number of the browsing request includes information. This transmission request is sent from the mobile terminal 3 to the base station 1 via the low speed uplink 5 to the base station 1
Be transmitted to. In response to this request, the base station 1 transmits the information on the relevant page to the mobile terminal 3.

According to this mode, by storing in the cache memory 19 the information of the page which is frequently requested to be viewed, for example, twice or more within a short period of time, such information is viewed. It is not necessary to transmit from the base station 1 each time a request is made, and the cache memory 19
It can be read from and viewed immediately. Note that such information frequently requested to be browsed is, for example, information about a page of a table of contents or information about a page in which an operation method is described.

In addition to the first and second modes described above, there is a third mode for continuously transmitting information over a plurality of pages from the base station 1 to the mobile station 3, a so-called broadcast mode. It is also possible.

FIG. 11 is a block diagram of a mobile communication system according to another embodiment of the present invention, and the network 8 and the database 9 shown in FIG. 1 are omitted in the figure. FIG.
1, the base station 1 has a radio circuit section 42 that transmits and receives to and from the mobile terminal 3 via the antenna 41, an error detection coding section 43 and a control section 44 for realizing error retransmission control.

On the other hand, the mobile terminal 3 in this embodiment has the configuration shown in FIG.
Is not variable transmission rate. That is, as shown in FIG. 11, the transmission / reception device 11 in the mobile terminal 3 is basically configured by removing the transmission quality estimation unit 26 from FIG. 4, but the base station 1 uses the error detection coding 43. The error detector 28 is disposed on the output side of the demodulator 24 due to the provision of the above.

The mobile terminal 3 uses the page number indicating the page of the information to be browsed (displayed) among the information stored in the database 9 as a browse request through the low speed uplink 5 as in the previous embodiment. Send to. Base station 1
Upon receiving this browsing request, the information of the page of the requested page number is fetched from the database 9 via the network 8 into the storage unit 7 and transmitted to the mobile terminal 3 via the high speed downlink 4. Here, the information transmitted to the mobile terminal 3 has a page structure composed of a plurality of fixed length frames as shown in FIG. 10, and the error detection coding unit 43 performs error detection coding on a frame-by-frame basis.

Thus, the high speed downlink 4 from the base station 3
The information transmitted for each frame via is received by the mobile terminal 3. Since each frame is error-detection coded, the receiving terminal 3 can detect whether or not the received frame contains an error by using the error detection unit 28. When an error is detected by the error detection unit 28, the control unit 27 of the mobile terminal 3 controls the transmission signal source 22 and the base station of the frame in which the error is detected is transmitted via the low-speed uplink 5. A request for resending is sent to No. 3.

In the present embodiment as well, as in the previous embodiment, there is no restriction on the page number requested by the mobile terminal 3 as a browsing request, and any page number desired by the user of the terminal 3 can be requested. . Therefore, the mobile terminal 3 can pre-read the information of the page that the user is likely to see next, and store it in the main memory 15 or the cache memory 19 in advance. The specific method for this pre-reading is the same as that of the previous embodiment, so the explanation is omitted.

By the way, in the present embodiment, since the retransmission request is issued in frame units as described above, the transmission time per frame differs between the frame in which an error is detected and the retransmission request is made and the frame in which the retransmission request is not made. The transmission time also depends on the number of requests. As a result, the transmission time of information per page also varies. However, if the prefetching is performed as described above in the same manner as in the previous embodiment, the information of the previous page or the next page is immediately browsed without a long waiting time regardless of such a difference in transmission time. be able to.

[0058]

As described above, according to the present invention, in a mobile communication system having a transmission / reception asymmetric structure capable of reducing the size and weight of a mobile terminal, a high-speed downlink from a base station to a mobile station in order to maintain a constant communication quality. Information of the previous page or the next page that may be viewed next while the user is browsing the desired page when the transmission speed of the is made variable or the retransmission control is performed from the base station to the mobile station. Is sent from the base station in advance and stored in the memory on the terminal side, so-called prefetching, or information for multiple pages that may be browsed is collectively sent from the base station to the mobile terminal and cache memory etc. By storing the information in a page that is not stored in the mobile station and transmitting it from the base station to the mobile station only when the information on the page corresponding to the input of the browsing instruction that is not stored is stored The time required for display of information to absorb the difference in the transmission speed of each page can be made constant regardless of the page, the operation of the mobile terminal is the effect of remarkably improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a mobile communication system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a mobile terminal in the embodiment.

FIG. 3 is a diagram showing a configuration of information stored in a database according to the embodiment.

4 is a block diagram showing a configuration of a transmission / reception variable transmission / reception apparatus in FIG.

FIG. 5 is a block diagram showing an internal configuration of a memory in the embodiment.

FIG. 6 is a diagram for explaining the operation of the memory of FIG.

FIG. 7 is a diagram showing a page structure of information in the present invention.

FIG. 8 is a diagram showing another example of a page structure of information in the present invention.

FIG. 9 is a diagram showing another example of the page structure of information in the present invention.

FIG. 10 is a diagram showing still another example of the page structure of information in the present invention.

FIG. 11 is a diagram showing configurations of a base station and a mobile terminal in a mobile communication system according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base station 2 ... Zone 3 ... Mobile terminal 4 ... High speed downlink 5 ... Low speed uplink 6 ... Low speed downlink 7 ... Storage part 8 ... Network 9 ... Database 10 ... Information 11 ... Mobile terminal antenna 12 ... Transmission rate variable transmission / reception Device 13 ... Input unit 13a ... Mode switching unit 14 ... CPU 15 ... Main memory 16 ... Display unit 17 ... DMA controller 18 ... Cache controller 19 ... Cache memory 20 ... Bus 21 ... Wireless circuit unit 22 ... Transmission signal source 23 ... Programmable filter 24 ... Demodulator 25 ... Clock generator 26 ... Transmission quality estimation unit 27 ... Control unit 28 ... Error detection unit 31 ... First memory (first storage area) 32 ... Second memory (second storage area) 33 ... Third memory (third storage area) 34 ... Selector 41 ... Base station antenna 42 ... Wireless Circuit part 43 ... Error detection coding part 44 ... Control part

Front page continuation (72) Inventor Nobuyasu Nakajima 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Inside the Toshiba Research and Development Center, Inc. (72) Inventor Hiroshi Ogura 1 Komukai-shiba-cho, Kawasaki-shi, Kanagawa Address Incorporated company Toshiba Research and Development Center (72) Inventor Katsuya Komukai Toshiba-cho, Saiwai-ku, Kawasaki City, Kanagawa 1 Incorporated Company Toshiba Research and Development Center (72) Inventor Tsutomu Sugawara Sachi-ku, Kawasaki City, Kanagawa Prefecture Komukai Toshiba Town No. 1 Inside Toshiba Research and Development Center, a stock company

Claims (7)

[Claims] 1. A base station and a mobile terminal, which transmit information from the base station to the mobile station via a high speed downlink, and transmit the information from the mobile terminal to the base station via a low speed uplink that is slower than the high speed downlink. In the mobile communication system for transmitting information by means of the above, the base station stores the information, which is managed in page units and in which each page is assigned a page number, and the mobile terminal stores the information accumulated by the storage means. In response to a browsing request from the information transmission means for transmitting at a variable transmission rate via the high-speed downlink, the mobile terminal, a page number according to the browsing instruction input by the user of the mobile terminal. Browsing request transmitting means for transmitting a browsing request to the base station via the low-speed uplink, and the base when the transmission rate of the high-speed downlink is less than or equal to a predetermined value. From the storage means for storing and holding the information transmitted from the storage means via the high speed downlink, and a display means for displaying the information of the desired page read from the storage means. Is less than or equal to a predetermined value, while the information of the desired page is displayed on the display means, the browsing request transmission means uses the page number of at least the page before or after the desired page as the browsing request. A mobile communication system, characterized in that the storage means captures and stores at least the information of the previous or subsequent page while transmitting the information to a station. 2. A base station and a mobile terminal, wherein information is transmitted from the base station to the mobile station via a high speed downlink, and the mobile terminal transmits the information to the base station via a low speed uplink which is slower than the high speed downlink. In the mobile communication system for transmitting information by means of the above, the base station stores the information, which is managed in page units and in which each page is assigned a page number, and the mobile terminal stores the information accumulated by the storage means. Information transmission means for transmitting via the high-speed downlink in response to a browsing request from the mobile terminal, and error retransmission for controlling the information transmission means to retransmit the same information in response to an error retransmission request from the mobile terminal. The mobile terminal has a control means, and the mobile terminal uses the page number corresponding to a browsing instruction input by a user of the mobile terminal as a browsing request to the base station. Browsing request transmission means for transmitting via the high speed downlink, storage means for storing and holding information transmitted from the base station via the high speed downlink, and information for a desired page read from the storage means. Display means and error retransmission request transmission means for transmitting the error retransmission request to the base station via the low speed uplink when detecting an error in information transmitted from the base station via the high speed downlink; While the information of the desired page is displayed on the display unit, the browsing request transmission unit transmits at least the page number of the page before or after the desired page to the base station as a browsing request. The mobile communication system, wherein the storage means captures, stores and holds at least the information of the previous or subsequent page. 3. A base station and a mobile terminal, which transmit information from the base station to the mobile station via a high speed downlink, and transmit the information from the mobile terminal to the base station via a low speed uplink which is slower than the high speed downlink. In the mobile communication system for transmitting information by means of the above, the base station stores the information, which is managed in page units and in which each page is assigned a page number, and the mobile terminal stores the information accumulated by the storage means. A plurality of pages transmitted from the base station via the high-speed downlink, the information transmitting unit transmitting the data in units of a plurality of pages via the high-speed downlink in response to a browsing request from the base station. Storage means for storing and retaining page information, and when the storage means stores page information corresponding to the viewing instruction input by the user of the mobile terminal Display means for displaying the information of the page read from the means, and when the storage means does not store information of the page corresponding to the browsing instruction input, a browsing request corresponding to the browsing instruction input is issued to the base. A mobile communication system, comprising: a browsing request transmitting means for transmitting to a station via the low-speed uplink. 4. A base station and a mobile terminal, wherein information is transmitted from the base station to the mobile station via a high speed downlink, and the mobile terminal transmits the information to the base station via a low speed uplink which is slower in transmission speed than the high speed downlink. In the mobile communication system for transmitting information by means of the above, the base station stores the information, which is managed in page units and in which each page is assigned a page number, and the mobile terminal stores the information accumulated by the storage means. From the high speed downlink in response to a browsing request from the mobile terminal, the mobile terminal, the page number according to the browsing instruction input by the user of the mobile terminal as the browsing request Information transmitted from the base station via the low-speed uplink and transmitted from the base station via the high-speed downlink is stored in a storage unit and stored in a desired page. While displaying the information of the desired page, at least the page number of the page before or after the desired page is transmitted to the base station as a browsing request to display at least the page of the previous page or the subsequent page of the desired page. A first mode in which information is captured and stored in the storage unit, and a plurality of pages of information transmitted from the base station via the high-speed downlink are stored in the storage unit and stored in the storage unit. When the information of the page corresponding to the browsing instruction input by the user of the mobile terminal is stored, the information of the page read from the storage unit is displayed, and the page corresponding to the browsing instruction input is displayed in the storage unit. The second mode in which a browsing request corresponding to the browsing instruction input is transmitted to the base station via the low-speed uplink when the information of No. And a mobile communication system characterized in that the first mode and the second mode are selectable. 5. The storage means stores a first storage area for storing and holding information on a previous page of a page on which the display means is currently displaying information, and information on a page for which current information is being displayed. A storage area of the second storage to be held, a third storage area to store and hold the information of the next page of the page currently displaying information, and an instruction to browse the previous page or the next page by the user of the mobile terminal. The information stored and held in the first storage area or the third storage area in accordance with the input is newly supplied to the display means as the information in the second storage area, and the third storage area or the first storage area is also supplied. The mobile communication system according to any one of claims 1, 2 and 4, further comprising: means for capturing information on a previous page or a next page transmitted from the base station in the area. 6. The base station transmits most of information to be transmitted to the mobile terminal as a plurality of fixed length blocks on the high speed downlink, and transmits the rest of the information from the high speed downlink. The mobile communication system according to any one of claims 1 to 5, wherein the mobile communication system transmits via a low-speed low-speed downlink. 7. The base station has means for transmitting attribute information corresponding to information transmitted by the information transmitting means to the mobile terminal via a low speed downlink whose transmission speed is slower than that of the high speed downlink. The mobile communication system according to any one of claims 1 to 6, which is characterized.