JP2000308135A - Mobile wireless terminal - Google Patents

Abstract

(57) [Summary] A mobile radio terminal capable of communicating with a single terminal while switching networks between a plurality of different mobile communication systems quickly. SOLUTION: Using software technology, software is constituted by a baseband processing unit 5, a download control unit 6, and a communication control unit 6, and software is downloaded via a layer 3 call control "user information" message.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile radio terminal for communicating while switching networks between a plurality of different mobile communication systems, and more particularly, to a software radio technology for obtaining software used for radio communication by downloading. It relates to the mobile radio terminal used.

[0002]

2. Description of the Related Art In recent years, portable telephones, PHSs, pagers, and the like have rapidly become widespread. And specifications are diversifying. That is, multimedia mobile communication that can communicate anytime, anywhere, with anyone, and with any data enables communication including not only voice but also images, moving images, data, characters, music, and the like. However, there are many types of mobile communication systems in the world, and there is no compatibility between them. Therefore, in order to actually travel around the world and carry out portable communication at any destination, prepare terminals for each mobile communication system,
Had to use a multimode terminal. To solve this problem, IMT2, a world unified system
000 are standardized by ITU-T, but until the standardization is realized, the existing system must be used. Conventionally, as a multi-mode terminal, for example, Japanese Patent Application Laid-Open Nos. 10-84583 and 10-84584 propose a device that prepares circuits corresponding to a plurality of systems in one terminal and switches between the circuits. According to these means, communication can be continued without interruption even when moving to a service area of a system using a different frequency or protocol.

[0003]

However, in a conventional multi-mode mobile radio terminal, a circuit corresponding to a plurality of systems must be prepared in one terminal, and it is smaller and lighter than a dedicated terminal of each system. However, there has been a problem that demands for reduction in power consumption and power consumption cannot be sufficiently achieved.
If miniaturization is attempted, there is a limit to the number of circuits that can be physically accommodated, so switching to a system with circuits is possible, but switching to a system without circuits is not possible. was there. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problem. Basic functions of a radio device, such as a modulation / demodulation process, which have conventionally been constituted by hardware, are implemented by software radio (S
R) A multi-mode mobile radio terminal that communicates while switching a network between a plurality of different mobile communication systems by writing in software using technology and downloading its basic functions.

[0004]

According to a first aspect of the present invention, there is provided a broadband wireless transmission / reception unit capable of wireless transmission / reception at a predetermined frequency in all bands, and transmission / reception by the wideband wireless transmission / reception unit. A / D-D / A conversion means capable of bidirectionally converting a wideband wireless analog signal and a wireless digital signal, and a digital signal including channel separation and modulation / demodulation processing for the wireless digital signal using software radio technology. A mobile radio having digital signal processing means capable of performing radio baseband processing required for radio communication and performing voice band data processing before and after the radio baseband processing and control processing of each unit of the mobile radio terminal including the above means Terminal, wherein the digital signal processing means is a software for defining a wireless function from a receiving line used for the wireless communication. The software, including software,
Downloading and storing software using radio technology, activating the stored software to at least perform the wireless baseband processing, selecting one of a plurality of different mobile communication systems, Communication between different mobile communication systems. According to a second aspect of the present invention, in the mobile wireless terminal according to the first aspect, the mobile wireless terminal performs a perch channel scan common to all systems at power-on, and performs a modulation scheme, an access scheme, and the like common to all systems. By setting the above parameters and receiving information common to all the systems, it is characterized in that what is the system of the peripheral base station is determined. In the invention according to claim 3, in the mobile radio terminal according to claim 1 or 2,
The software is downloaded as a message using a control channel.
According to a fourth aspect of the present invention, in the mobile radio terminal according to any one of the first to third aspects, the download of the software is performed by a “user information” message of a layer 3 call control in an open system interconnection (OSI) model. It is performed through a "user / user" information element.
According to a fifth aspect of the present invention, in the mobile radio terminal according to any one of the first to third aspects, the software download is performed by a layer 3 radio management message or a mobility management message “operator-specific” in an open system interconnection (OSI) model. Information ". According to a sixth aspect of the present invention, in the mobile wireless terminal according to any one of the first to fifth aspects, the software defining the wireless function to be downloaded includes at least the software to be requested. A software request including information indicating the type, a software response including information indicating the type and version of the software to be responded, and information indicating the type of software to be downloaded and the start and end of the download And a download response including information indicating the type of software to be downloaded, the start and end of the download, and whether the download can be accepted, and information indicating the number of the divided download data. Indicates the download data and the number of the divided download data Characterized in that it comprises a download data check including broadcast, the definition of each embedded message with software switch including information indicating a software type and version downloaded. In the invention of claim 7, in the mobile radio terminal according to any one of claims 1 to 6, the mobile radio terminal measures reception states of signals from a plurality of base stations, and the reception state changes. When switching to another channel or another system, wherein the reception state is any one of electric field strength, word error rate, bit error rate, or a combination of two or more thereof And According to a seventh aspect of the present invention, in the mobile radio terminal according to the seventh aspect, the reception state is a function of an electric field strength determined for each mobile communication system.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a software radio technology (hereinafter, referred to as SR) used in the present invention will be described. The SR realizes the basic functions of the wireless device such as the modulation / demodulation method and the access method by software. The basic function of the wireless terminal can be easily changed only by rewriting the software without changing the hardware. Things. The “system extension” function in the SR terminal is performed by download, for example, via radio,
The limitations of technologies that depend on hardware as described above also
VHDL (Verilog Hard)
ware Discript Language) can be overcome by downloading. For details on SR, see Joe Mi
tola: “The Software Radio Architecture”, IEEE C
ommunications Magazine, Vol.33, No. 5, pp. 26-38
(May 1995).

An embodiment of the present invention will be described below in the order of a hardware configuration, a software configuration, handling of software to be downloaded, and a download sequence, based on the embodiment shown in the drawings. FIG. 1 is a schematic configuration diagram showing a general hardware configuration of a terminal using an SR according to the present invention. As shown in FIG. 1, the terminal includes an antenna 1, an RF converter 2, a wideband A / D-D / A
It is composed of a conversion unit (hereinafter, referred to as an AD unit) 3 and a software processing unit 4. The software processing unit 4 further includes
It comprises a wireless baseband processing unit 41, a data processing unit 42, and a control unit 43. In the above configuration, the software processing unit 4 is a part to which software download, which is a feature of the present invention, is applied. Among them, the wireless baseband processing unit 41 is particularly configured by hardware in the related art. This is the part that has not been processed by the software, and therefore has not been targeted for download.

The operation of the terminal having the above configuration is as follows. The wideband signal input from the antenna 1 is converted to an intermediate frequency IF by the RF converter 2. This IF signal is sent to the AD unit 3 as it is in a wide band. The AD unit 3 collectively converts the input wideband signal into a digital signal and outputs the digital signal to the wireless baseband processing unit 41 in the software processing unit 4. The wireless baseband processing unit 41 performs “channel processing” of bit operations such as channel separation, modulation / demodulation, and error correction using the SR technique. Although the processing of the wireless baseband processing unit 41 is performed by hardware in the conventional configuration, this terminal uses a DSP (Digital Sign).
al Processor) on a high-speed programmable processor. Wireless baseband processing unit 4
The audio and the like among the digital signals from
2 and the communication control data is sent to the control unit 43. The control unit 43 performs wireless line control, call connection control, and the like based on the communication control data sent from the wireless baseband processing unit 41, and has two systems for data to be downloaded. The data processing unit 42 performs data processing of a facsimile, a modem, and the like, in addition to voice processing. In the above, the outline of the operation of the terminal at the time of wireless reception has been described. Conversely, when a transmission signal is transmitted from the wireless baseband unit 41, the transmission signal is D / A-converted by the AD unit 3 and RF-converted. Part 2
, And is transmitted to a base station or the like via the antenna 1.

Next, the configuration of software in the hardware shown in FIG. 1 will be described. FIG. 2 is a software configuration diagram of the wireless communication terminal using the SR, and includes a baseband processing unit 5, a download control unit 6, and a communication control unit 7. The baseband processing unit 5 includes the basic functions described in the wireless baseband processing unit 41 of FIG. 1 described above, performs channel separation processing 51, modulation / demodulation processing 52, and bit stream processing 53, and is downloaded. This is software that performs software processing. The download control unit 6 controls download of software, and download data transmitted from a network via a communication control unit 7 described later,
It operates according to control commands sent before and after the data. In addition, it controls transmission and reception of signals of the baseband processing unit 5. The communication control unit 7 is the same as a conventional terminal, and is shown in detail in FIG.

FIG. 3 is a diagram showing a software structure of the communication control unit 7 shown in FIG. 2. In FIG. 3, an OSI layer structure is adopted. In FIG. 3, a higher layer unit (HMI) 17
Performs dial input from a keyboard, display of various information on an LCD, and the like. Layer 3 (RT, MM, CC) unit 1
5 and a higher layer (RT, MM, CC) 16, which is an upper layer (referred to as a service layer), both have a radio management function (RT), a mobility management function (MM), and a call processing function (CC). Have. Radio management function (RT: Radio Frequ
The term “ency transmission management” means the control of a wireless line, and a mobility management function (MM).
t) means location registration and authentication. The call processing function (CC: Call Control) means a call connection control for outgoing call, incoming call, and the like. 931 is performed. The layer 2 unit 14 indicated as layer 2 performs link access processing (LAPDM: Link Access Procedure).
for Digital Mobile channel) and ITU-T
Q. 921 is performed. Leia 1 part 13
An instruction is given to the frame synchronization, channel coding of the data frame, and the baseband processing unit 5. Under the control of the management 11, each layer integrates and transmits and receives signals to and from the network. The software shown in FIGS. 2 and 3 operates on a real-time OS. As described above, as the software of the present embodiment, the baseband processing unit 5 to be downloaded, the download control unit 6 and the communication control unit 7 are separately configured.

Next, handling of software to be downloaded will be described. The method of downloading from the network side to the wireless communication terminal is basically performed by wireless as described above. In this method, the program data to be downloaded is stored in the "user information" in the same manner as voice and modem data. As the information channel (T
CH) and a "message" related to communication control transferred at layer 3 as a control channel (CCH).
There is a way to send. In general, program data such as software is not a “message” related to communication control, and it is considered appropriate to handle it as “user information”. However, since data such as voice, facsimile, and modem are transmitted as "user information" during communication, normal services cannot be used during downloading, and during the communication of "user information", It is impossible to download software. Therefore, in the embodiment of the present invention, the program data can be handled as a “message”. By doing so, it becomes possible to perform software download using the control channel (CCH) while transmitting voice and the like using the information channel (TCH). The message used for the download is a “user information” message of the layer 3 call control. The reason is that the message transmission procedure and coding are defined and general, and that the call control message has a retransmission control function because it is transmitted in one layer 2 frame. In addition, since the message of the standard is used for both the “user information” message and one frame of the layer 2, consistency with the existing system can be maintained.

The specific usage of the "user / user" information element, which is defined as one of the elements of the "user information" message, is not specified in the standard, so the message is embedded therein and the "user information""To send and receive. Message embedded in user information (hereinafter “embedded message”
) Are defined as follows. (1) Software version request: Information indicating the type of software to be requested (for example, communication control, wireless baseband, download control) is included. (2) Software version response: The type of software to be responded and its version information are described. (3) Download control: Information indicating the type of software to be downloaded and the start / end of download is described. (4) Download response: Information indicating the type of software to be downloaded, start / end of download, and whether or not download control has been accepted. (5) Download data: Download data and information indicating the number of divisions are listed. (6) Download data confirmation: Information indicating the number of division of the confirmed data is included. (7) Software switching: The type of downloaded software and its version information are listed.

Next, a software download sequence will be described. FIG. 4 is a message sequence chart (hereinafter, referred to as a sequence diagram) showing an outline of downloading according to the embodiment of the present invention. In the figure, (1) software version check: the network requests the terminal software version (S1), and the terminal returns the version (S2). (2) Start of download: The network sends a download start command (S3), and the terminal responds to this (S4).
return it. (3) Download: The entire data is divided and downloaded from the network to the terminal (S5). During downloading, an error check or the like is appropriately entered. (4) Download end: When the download of the entire data is completed, the network sends a download end command (S6), and the terminal returns a response (S7). (5) Software switching: The network sends a software switching command (S8), and the terminal switches to the newly downloaded software.

FIG. 5 shows the details of the download (S5) shown in the sequence diagram of FIG. In FIG. 5, the entire downloaded program is divided into a plurality of bytes so as to be included in a “user / user” information element. A unit for performing retransmission control between a network and a terminal is called a window, and one window is used.
Consists of N bytes. The whole data to be downloaded is first divided into M windows (Win
= 1 / M to Win = M / M). Each of the M pieces of download data is sequentially transmitted with a further number (Div = 1 / N to Div = N / N) for each window. This number is called Division.
In FIG. 5, upon receiving the N pieces of data (S51 to S53), the terminal returns a response (S54) indicating that reception of the window (Win = 1) has been confirmed. The network is
If the transmission of one window succeeds in response to the response (S54), the next Window (Win
= 2) are transmitted in order (S55 to S56).

[0014] Here, for example, on the terminal side, Windows
If the reception of (Win = 2) fails, a confirmation response (S57) is not returned to the network, and the network retransmits the entire data of the window (Win = 2). Hereinafter, the last Window (W
in = M) is transmitted from the network (S58),
The response (S59) is returned, and until all windows have been downloaded, W
The download process of the window is repeated.

In the embodiment of the present invention, as shown in FIG. 3, downloading is performed using the information element "user / user" of the layer 3 call control message "user information". This enables downloading via the control channel while performing voice transmission via the information channel. Further, since the standard message is used, consistency with the existing system can be maintained.

As described above, in the embodiment of the present invention, the SR
By providing a software download function to mobile wireless terminals using technology, it is possible to standardize system specifications before deciding on standardization of system specifications, as in the case of conventional changes by downloading system software at base stations in networks. Immediately after the determination, the mobile radio terminal can provide the system service newly standardized. For example, TDMA and CD
If dual mode terminals of different access schemes such as MA are realized according to the present invention using the above-described SR technique, channel distribution, modulation / demodulation processing, bit stream Even in the case of changing to the other method of software related to the basic function of the wireless device such as processing, it is possible to correspond to a different communication method without changing the hardware by downloading through a wireless communication line. More specifically,
This is effective when applied to a dual mode device of a digital mobile phone (PDC) and a CDMA mobile phone.

In the above description, the message used for downloading is described as "user information" for call control, but may be "operator-specific information" for radio management or mobility management. When the "operator-specific information" message is used for downloading, there is no stipulation on the transmission procedure, coding, and usage, and all the operations are required by the operator.
In addition, since the radio management message and the mobility management message are transmitted in a layer 2 UI frame, there are advantages that the header is less and the transmission speed is higher than that of the I frame.

Next, switching to another channel or another system will be described. FIG. 6 is a flowchart showing the switching operation to another channel. In the figure, a portion surrounded by a broken line is a channel switching condition determination block. In the figure, the terminal is in standby or during communication,
The electric field intensities of the radio waves emitted from a plurality of peripheral base stations are constantly measured, and these are compared to create a table in which the codes of the base stations are arranged in the order of strong radio waves. L0 is the reception level of the base station in communication, Lm is the maximum reception level of the peripheral base stations, Lt1 is the standby deterioration level, Lt2 is the standby permission level, and ΔL = Lt1-Lt2 is the zone transfer level difference. The switching information is stored in the terminal in advance or notified from the base station. The terminal switches channels when a predetermined criterion is satisfied. Note that by downloading software at the time of channel switching, switching to another system can be performed, and a multi-mode mobile wireless terminal can be realized. As described above, the example in which the switching to another channel or another system is performed based on the electric field strength has been described, but the word error rate or the bit error rate may be used as the parameter indicating the reception state. If two or more of them are used in combination, the reception state is represented in more detail, so that it is more effective to indicate a trigger for switching. Further, by using a function of the electric field strength determined for each system as the reception state, it is possible to correct the coverage area of the base station and the modulation method which differ for each system.

The system switching operation in the terminal shown in FIG. 6 is system switching during standby or communication, and the system is determined at power-on as follows.
FIG. 7 is a flowchart showing a perch channel scanning operation at the time of power-on. When the terminal is turned on, the terminal measures the electric field strength of the radio wave of the peripheral base station by the scanning operation according to the above-mentioned flowchart, compares them, and creates a frequency table in the order of the electric field strength. This operation is similar to the above-described operation during standby, but is characterized in that the frequency for measuring the electric field strength is common to all systems.

FIG. 8 is a flow chart showing a system decision operation at power-on. In addition to setting the frequency at the top of the table, parameters such as a modulation method, an access method, and a bit rate common to all systems are set (S
1) Check layer 1 such as frame synchronization and CRC (S2). The above operation is the same as the above-described operation during standby, but is characterized in that parameters such as the modulation method and access method to be set are common to all systems. After setting the parameters, information common to all systems is received (S3). Since the common information includes the frequency, channel structure, modulation scheme, access scheme, frame format, and the like of the system serving in the area of the common base station, the standby system is determined based on the information ( S4), and shift to standby. If the common information cannot be received, the last channel is checked (S5), and the channel setting (S1) is performed again. Here, conventionally, it was checked whether or not a combination of parameters remains. However, in the present invention, since the parameters are common to all systems, it is not necessary to check the combination, and the system can be determined quickly. Thus, the next frequency in the table is received until the common information can be received. As described above, the terminal according to the present invention performs a perch channel scan common to all systems when the power is turned on, sets a common modulation scheme, an access scheme, and the like for all systems, and receives common information, thereby enabling Know what the base station system is. Therefore, the system can be determined promptly, and the terminal can be used immediately.

[0021]

As described above, in the mobile radio terminal according to the present invention, the software is constituted by the radio baseband processing unit, the download control unit and the communication control unit using the SR technology, and the layer 3 call control "user Software downloads via the "Information" message,
The basic function itself such as the modulation / demodulation method in the mobile radio terminal can be easily changed, and a multi-mode mobile radio terminal can be realized. Further, when the power is turned on, a perch channel scan common to all systems is performed, a modulation method and an access method common to all systems are set, and the common base station is received to determine what the peripheral base station system is. As a result, the system can be determined at power-on at high speed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a hardware configuration of a mobile radio terminal according to the present invention.

FIG. 2 is a schematic configuration diagram showing a software configuration of the mobile radio terminal according to the present invention.

FIG. 3 is a schematic configuration diagram of a communication control unit in FIG. 2;

FIG. 4 is a sequence diagram showing an outline of downloading software according to the present invention.

FIG. 5 is a sequence diagram showing details of software download according to the present invention.

FIG. 6 is a flowchart illustrating a channel switching method during communication and standby.

FIG. 7 is a flowchart showing a perch channel scanning operation at power-on.

FIG. 8 is a flowchart showing a system determination operation at power-on according to the present invention.

[Explanation of symbols]

1. Antenna, 2. RF converter, 3. Broadband A /
DD / A conversion unit, 4 software processing unit,
5 Baseband processing unit 6 Download control unit 7 Communication control unit 11 Management unit 12 Real-time OS unit 13
Layer 1 part, 14 layer part, 15 layer part, 16 higher layer part (RT, MM, CC),
17. Higher-order layer unit (HMI), 41: wireless baseband processing unit, 42: data processing unit, 43: control unit, 51: channel separation processing, 52: modulation / demodulation processing, 53: Bitstream processing

Claims (8)

[Claims] 1. A broadband wireless transmission / reception means capable of wireless transmission / reception at all predetermined frequencies, and a wideband A capable of bidirectionally converting a wideband wireless analog signal and a wireless digital signal transmitted / received by said wideband wireless transmission / reception means. / DD /
A radio means for performing radio baseband processing necessary for digital radio communication including channel separation and modulation / demodulation processing on the radio digital signal using software radio technology, and voice band data processing before and after the radio baseband processing. And a digital signal processing unit capable of performing control processing of each unit of the mobile wireless terminal including the above units, wherein the digital signal processing unit has a wireless function from a receiving line used for the wireless communication. Download and store software using the software / radio technology, including software defining software, and activate the stored software to perform at least the wireless baseband processing; Select one of the systems to communicate between multiple different mobile communication systems Mobile radio terminals, characterized in that the capacity. 2. The mobile radio terminal performs a perch channel scan common to all systems at power-on, sets parameters such as a modulation scheme and an access scheme common to all systems, and receives information common to all systems. The mobile radio terminal according to claim 1, wherein the mobile radio terminal determines what the system of the peripheral base station is. 3. The mobile radio terminal according to claim 1, wherein the download of the software is executed as a message using a control channel. 4. The download of the software is performed via a “user user” information element of a “user information” message of a layer 3 call control in an open system interconnection (OSI) model. Item 1
4. The mobile wireless terminal according to any one of claims 3 to 3. 5. The method according to claim 1, wherein the software is downloaded via a layer 3 radio management message or a mobility management message “operator specific information” in an open system interconnection (OSI) model. The mobile radio terminal according to the above. 6. The software defining the wireless function to be downloaded includes at least a software request including information indicating a type of software to be requested, and a type of software to be responded to. Software response including information indicating the version, download control including information indicating the type of software to be downloaded and start and end of download, type of software to be downloaded and start and end of download And a download response including information indicating whether the download is accepted, and download data including information indicating the number of the divided download data,
It is characterized by including definitions of each built-in message of download data confirmation including information indicating the number of divisions of the confirmed download data and software switching including information indicating the type and version of downloaded software. The mobile radio terminal according to claim 1. 7. The mobile radio terminal measures reception conditions of signals from a plurality of base stations, and switches to another channel or another system when the reception conditions change,
The mobile station according to any one of claims 1 to 6, wherein the reception state is one of an electric field strength, a word error rate, and a bit error rate, or a combination of two or more thereof. Wireless terminal. 8. The mobile radio terminal according to claim 7, wherein the reception state is a function of an electric field strength determined for each mobile communication system.