Method for performing inter-terminal communication via plural wireless data networks

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to wireless communication, and particularly to the field of mobile communication via multiple wireless data networks.

【0002】

[Conventional technology]

Currently, users of wireless communication devices are restricted to wireless data networks that support their wireless communication devices. For example, outside the radio frequency area that covers one wireless data network, the user usually does not have another wireless means of communication available. Similar problems occur during busy times when a wireless data network cannot accommodate any more users.

【0003】

At the same time, the user of the wireless communication device cannot communicate with the fixed communication device of another network or with another wireless communication device using the interface protocol of another wireless data network. Therefore, it is limited to communication with other users who have the same wireless data network interface protocol that the mobile terminal user is still using. Therefore, the user of the mobile terminal (mobile phone) is separated from the user on another data network.

【0004】

[Problems to be Solved by the Invention]

The present invention is to provide a seamless data communication system that provides a wireless communication device that can operate across a plurality of wireless data networks. Therefore, an object of the present invention is to provide a device and a method for supporting a plurality of wireless data communications between a wireless communication device and a fixed or wireless communication device using a network protocol different from the protocol of the wireless communication device. That is.

【0005】

[Means for solving problems]

In a wireless communication device, the wireless communication device of the present invention uses a protocol converter that converts an in-band message coming from a certain network protocol into a network protocol that can be used by an end processor in the wireless communication device. For out-of-band messages originating from this wireless communication device, the protocol converter converts the end processor network protocol into a network protocol for networks that can communicate with fixed communication devices.

【0006】

Conversions between different protocols require extracting user data from in-band data message frames and placing this user data within network frames available to the destination network protocol. The protocol converter sends this converted data message between the end processor and the radio frequency modem.

【0007】

On the fixed network side, the fixed communication device of the present invention is connected to a router connected to a network capable of communicating with the wireless communication device. The router translates incoming data messages from network protocols used by wireless communication devices into network protocols used by fixed communication devices, and delivers this data messages from incoming networks to fixed communication devices. Conversion between different network protocols extracts user data from a network data message frame and places this user data within the network frame used by the destination network. The router also sends this converted user data to the fixed communication device.

【0008】

BEST MODE FOR CARRYING OUT THE INVENTION

Currently, mobile terminal users are usually unable to communicate over multiple wireless data networks. For example, cellular digital packet deta (CDPD) users can only communicate over a CDPD wireless network, and are therefore isolated from users on another communication network. The present invention attempts to remove the above limitation so that a mobile terminal user can select a network from a plurality of wireless data networks in order to perform wireless communication.

【0009】

According to the present invention, a protocol conversion is performed to convert an out-band data message from a wireless communication device into a format that can be used by the air interface protocol of the selected wireless data network, and wireless communication is performed from the selected wireless data network. Performs a network conversion that converts in-band data messages entering the device into a format that can be used by the end processor of the mobile terminal device, and when the in-band message is received, delivers the data message to the end processor or out-band message. Is transmitted to a network RF modem that wirelessly transmits to the selected wireless data network.

【0010】

Figure 1 shows the architecture of the entire system that performs wireless data communication over multiple networks. On the fixed network side, the fixed communication device (FTD) 101 is connected to the router 104 by wire. Multiple wired connection options may exist for connecting fixed communication devices to routers. Figure 1 shows an example using a connection between a public switched telephone network (PSTN) and an ISDN interface.

【0011】

Wired connections between the public switched telephone network (PSRN) 102 and the fixed-line communication device 101 and between the router 104 and the PSTN 102 have an ISDN B channel. Since this ISDNB channel is known, its detailed operation and configuration will not be described in detail. Fixed communication devices include any communication device that does not move.

【0012】

On the wireless network side, the wireless communication device 108 can transmit over a plurality of networks A, B, C, and X (107) that can be used. The network 107 is connected to the associated network gateways A, B, C, X (106), which convert the wireless communication information from the wireless communication device 108 into a protocol available to the LAN 105. The LAN 105 is interconnected to a wired network that includes a fixed communication device 101.

【0013】

The router 104 in FIG. 2 has two sub-routers, namely a master router 202 and a slave router 201. The master router 202 and the slave router 201 perform a dual function of translating and delivering (routing) data messages across a plurality of wireless data networks. The slave router 201 and the master router 202 are connected to a fixed communication network such as PSTN102 and further connected to LAN105, which LAN105 is further connected to network gateway 106.

【0014】

The network gateway 106 converts the information of the protocol used in the fixed communication network (102) into the protocol used in the network 107. The network 107 carries wireless information to and from wireless communication devices. Router 104 has ISDN / BRI209 on the PSTN network side. In-band data from wireless communication devices that span multiple wireless data networks is converted by the router from the wireless data network protocol to the network protocol used by the fixed communication device. This translated router delivers the data message to the network address of the fixed communication device.

【0015】

Out-of-band data messages from fixed-line communication devices that span multiple wireless data networks are translated by the router from the network protocol used by the network, including the fixed-line communication device, to the wireless data network protocol used by the destination wireless communication device. Ru. This converted router delivers the data message to the network address of the destination wireless communication device via the network gateway 106.

【0016】

This router includes a maintenance subsystem 212 that performs failure recovery, redundancy, traffic measurement, and diagnostics. If a system failure occurs in one of the subrouters 201 and 202, traffic is automatically switched to the other subrouter. The latest route table 214 is maintained, and if the network address changes with respect to the message received from network 107, it is updated in shape.

【0017】

The route table 214 is updated when it is determined from which network 107 the data message came from. Any new message sent to the network will be delivered to the correct address using this correct message format and by retrieving the receiver location from route table 214. Database 216 is maintained by accumulating user profiles for users of this active mobile phone for any active wireless communication device.

【0018】

Each message received by Router 104 is monitored using the received user data to determine if it is the correct message type and invalid messages are discarded. All messages received by the router are authenticated by monitoring the user identifier (ID) and the source network address in the data message.

【0019】

When a data message is received by the appropriate destination network control center (not shown), the data message is delivered over the destination network to the destination base station, where wireless access is provided to the wireless communication device. And be registered. At the base station, this data message is transmitted to the wireless communication device via radio frequency (RF) transmission and received by the protocol converter of the wireless communication device according to the present invention.

【0020】

Figure 3 shows the internal system architecture of the protocol converter 300 for wireless communication devices. The functional block of the protocol converter 300 includes a synchronization / control unit (T & C) 301, an end processor interface (EPI) 302, a configuration / control unit (C & C) 303, and an internetwork control unit (INC) 304. The function is easily understood by those skilled in the art. Internal ports A, B, C (305) provide interface connectivity to network radio frequency modems (NRFM) A, B, C (306). This protocol converter has a number of ports corresponding to number X of 307. The EPI provides an interface connection to the end processor (EP) 308 of the wireless communication device.

【0021】

In wireless communication devices, data messages are received via one of several different network RF modems 306. This network radio frequency modem 306 is used by wireless communication devices for wireless communication. A number of different network radio frequency modems 306 are connected to the protocol converter 300, which performs functions similar to a router on the network side.

【0022】

This protocol converter 300 has dual functions (ie, 1) the ability to convert in-band and out-band data messages to the required wireless data network protocol, and 2) the ability to deliver this converted data message). To execute. Out-of-band messages from wireless communication devices are converted by a protocol converter from the network protocol used by the wireless communication device's end processor 308 to the required network air interface protocol used for wireless communication.

【0023】

This translated out-band message is then converted by a protocol converter into the required one of several different wireless network 306s, where it is sent over the RF to the network base station of the required wireless data network. .. In-band messages received from one required of several different wireless network RF modems are translated from the wireless network air interface protocol required by the protocol converter to the network protocol used by the end processor of the wireless communication device. .. The protocol converter then delivers the translated data message to the end processor 308 of the wireless communication device.

【0024】

The operation of the present invention is generally used in a device consisting of a fixed communication device of an automatic train control system (ATCS) and an ATCS wireless communication device using a CDPD air interface network for wireless access. The operation and configuration of the elements of the CDPD and ATCS systems will not be described in detail as they are known to those skilled in the art.

【0025】

Explaining with reference to FIG. 2 using the example of a mobile terminal, the fixed communication device delivers the ATCS data message to the router 104 via ISDN / BRI209. This data message includes multiple Open System Integration (OSI) layers, where layer 1 is the physical layer in which multiple bits move through several media.

【0026】

When the router 104 receives the message, its user data and header information (ie, source and destination addresses, user ID, time stamp, message type, etc.) are checked to ensure accurate and authenticated transmission. Any message error is reported to maintenance subsystem 212. Route table 214 and database 216 are used as criteria for translating ATCS data messages into the correct destination network format and delivering the data messages to the correct destinations and addresses of active mobile phone users.

【0027】

Database 216 holds the user profile of each active mobile phone user. Route table 214 holds source network information for data messages received through the network gateway. The correct message format and destination address for all out-of-band messages are found in these tables and executed by the router.

【0028】

As shown in FIG. 4, in the fixed communication device that started the data transmission, the user data 406 is extracted from the ATCS frame 403 and input to the CDPD frame 404 having the necessary CDPD network information 401. The converted CDPD data message is then delivered to the home CDPD network control center of the wireless communication device via the CDPD gateway.

【0029】

In the Home Mobile Data Intermediate System (MD-SI), CDPD data packets are delivered to the Mobile Data Base Station (MDBS) where the destination wireless communication device is registered. To. When a CDPD data packet is received on the MDBS, it is sent over the RF to the CDPD RF modem in the wireless communication device.

【0030】

When received by the CDPDRF modem, this data packet is again converted to an ATCS data packet used by the end processor and delivered to the end processor by wire. This conversion process is performed by the protocol converter shown in FIG. The protocol converter extracts user data 406 from CDPD frame 404 and inputs this user data 406 to ATCS frame 403 with the required ATCS link layer 402.

【0031】

This process is reversed for wireless data transmissions originating from mobiles. The end processor delivers the ATCS data message to the protocol converter. User data is extracted from the ATCS frame by the protocol converter because the protocol conversion is required and it is input to the CDPD frame with the required CDPD network information. The CDPD frame is then delivered by a protocol converter to the CDPDRF modem, where the communication device is wirelessly transmitted to the network MDBS used for wireless access.

【0032】

The data packet is then delivered to the network MD-IS and then to the router. At the router, the data packet is again monitored and authenticated to verify the correct data transmission (ie, source and destination addresses, user ID, message type, time stamp, etc.). Any message error will be notified to the maintenance subsystem of the router. Once authenticated, the user data 406 is extracted from the CDPD frame 404 by the router and placed in the ATCS frame 403 with the required ATCS link layer 402.

【0033】

[Effect of the invention]

As described above, the present invention has been described using ATCS-CDPD as an example, but the present invention is not limited to these two wireless data networks, and is a wireless protocol used for an end processor of a fixed communication device or a wireless communication device. It also applies to multiple wireless data networks that enable wireless data communication across multiple wireless data network protocols regardless of type. Further, although the present invention has been described using an example from a fixed terminal to a mobile terminal, the present invention is not limited to wireless communication between a mobile terminal user and a fixed communication device, and can be applied between a plurality of mobile terminal users.

[Simple explanation of drawings]

[Figure 1]

Block diagram showing a multiple network wireless data communication system between terminals according to the present invention. [Figure 2]

Block diagram showing the internal structure of the router of the present invention [Fig. 3]

Block diagram showing the internal structure of the protocol converter of the present invention [Fig. 4]

Block diagram showing the process of the protocol converter of the present invention [Explanation of symbols]

101 Fixed Communication Device (FTD) 102 Public Switched Telephone Network (PSTN) 104 router 105 LAN 106 Network gateway 107 Network 108 Wireless communication device 201 Slave router 202 Master Router 209 ISDN / BRI 212 Maintenance subsystem 214 route table 216 database 300 protocol converter 301 Sync / Controller (T & C) 302 end processor interface 303 Consolidation / Control Unit (C & C) 304 Inter-network controller (INC) 305 internal port 306 Network Radio Frequency Modem 308 end processor 401 CDPD network information 402 ATCS Link Layer 403 ATCS frame 404 CDPD frame 406 User data