Nomadic translator or router

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DESCRIPTION

Nomadic transmitter or router.

Technical field

The present invention generally refers to the technique of digital communications, and more specifically to a portable transmitter or router that allows a user digital communication terminal to be transparent in both location and device.

Context technique

The user's digital communication addresses such as Internet and IP addresses are generally associated with a fixed physical location, such as the user's telephone line. However, portable communication devices such as laptops are becoming increasingly popular, making it common for a user to access the internet from locations as diverse as hotel rooms or airplanes.

Digital communication networks are established for route communications directed to a communication address to the associated physical location. Therefore, if a laptop is connected to a remote location, communications to and from the computer will not be associated with the user's communication address.

In order for a computer (host) to communicate over a network (for example, the internet), software protocols (for example, Transport Control Protocol / Internet Protocol (TCP / IP)) must be loaded into the Guest. A host computer sends information (for example, data packets) to devices on the network (routers) that receive the packets and send the packets back to the destination host.

The destination host will send responses back using a similar process. Each host computer and router must be configured so that it knows who to send data packets to. A router will receive packets only if the host computers specifically send (direct) the packets to that router. If a host is configured incorrectly (wrong address), then the host computer will be unable to communicate.

With the advent of mobile computers (laptops) and the desire to connect them to multiple networks to gain access to resources on the network and the Internet, a laptop must be configured for each network to which it connects. Traditionally this new configuration can be done either (i) manually in the software on the laptop (usually causing the mobile computer to reboot to load it into the new configuration), or (ii) with a new set of protocols to be used on mobile computers to obtain the configuration information of a device on a network to which the computer is connecting. When creating new services (protocols) to add functionality to host computers, these new protocols must be loaded onto the host computers or routers, depending on the type of functionality being added.

EP 0 560 706 describes a terminal adapter interface between a data termination equipment and a structural relay or a switched multimegabit data service telecommunication network for the type of network over which the data termination equipment is communicating be transparent. The terminal adapter implements links from one protocol to another for native structural relay data termination equipment to access a switched multimegabit data service telecommunication network and for data service telecommunication termination equipment native switched multimegabit can access a structural relay network. The address binding method carried out by the terminal adapter uses a parallel table lookup technique.

Description of the invention

In accordance with the present invention, a "Nomad" portable router or transmitter allows a portable computer or other portable terminal that is configured to connect to a home local network to connect to another location on the Internet or other digital data communication system. The nomadic router automatically and transparently reconfigures the terminal to its new location and processes the incoming and outgoing data.

According to a main embodiment of the present invention a transmitter is provided for connecting a host device to a communication device, the host device being configured to connect to a local device, the transmitter comprising: an internal interface for connection to the transmitter and to the host device; a system interface for connecting the transmitter with the communication device; and a processor; where the processor intercepts and is configured to translate data from the interfaces and allow the host device to automatically connect to the communication device. The present transmitter is characterized in that the processor is configured to automatically configure itself with the communication device operating in a promiscuous mode in which it accepts all incoming data and extracts the information from the communication device therefrom.

According to another embodiment of the present invention a digital storage medium is provided for storing a computer program. The digital storage medium implements after its execution the functionality of

ES 2 290 986 T3 a transmitter to carry out data translation between a host device that is configured to connect to a home device, a communication device, the program by intercepting and translating data from the interfaces and allowing the host device automatically connect to the communication device. It is also characterized in that the processor is configured to automatically configure itself to the communication device operating in a promiscuous mode in which it accepts all incoming data and extracts the information from the communication device from it.

The nomadic router includes a processor that appears as the home network with the terminal, and appears as the terminal with the communication system. The terminal has a permanent address, the nomadic router has a router address, and the terminal transmits the outgoing data to the system including the permanent address as the source address. The processor translates the outgoing data by substituting the permanent address for the router address as the source address. The terminal receives the incoming data from the system including the router address as the destination address, and the processor translates the incoming data by substituting the router address for the permanent address as the destination address.

The terminal can connect directly to one point on a local network, and the nomadic router can connect to another point on a network. The nomadic router can be used to implement numerous applications including nomadic email, network record synchronizer, database synchronizer, instant network, nomadic internet, mobile virtual private network and router for trade show, and it can also be used as a router. fixed nomad.

The nomadic router can be implemented as software and / or hardware. The nomadic router establishes location and device transparency for a digital communication terminal such as a laptop. The terminal can be connected to any variety of networks and locations that can employ a variety of communication interface devices.

The nomadic router automatically converts the actual location address to a communication address unique to the user such as an internet address, such that the terminal carries out communications originating from the communication address regardless of the physical location of the user. terminal.

The nomadic router can automatically configure the terminal to use a device selected from the interface devices, and it connects from one to the other if the first device is malfunctioning or unavailable.

The nomadic router includes software and services that can be packaged in a portable personal device to support a broad set of computing and communication capabilities as well as services to accommodate nomadic (user) mobility in a transparent, comprehensive and convenient way. This is achieved by providing device transparency and location transparency to the user.

There is a wide range of alternatives to communication devices such as Ethernet, Wireless LAN, and modem over the phone between which the user connects when he is in the office, moving around the office, or on the road (as in a hotel, airport , home). The transparency of the device in the nomadic router provides untethered connection between these devices (easily, transparently, intelligently, and without loss of session. Location transparency support in the nomadic router prevents users from having to reconfigure (eg IP and input address) their network device (laptop) every time they move to a new network or subnet.

The present nomadic router provides a separation of location and identity by providing a transparent IP address to the network device (host). The nomadic router provides independence between the location, the communication device, and the host operating the system. There is no need to adopt new criteria by the networking community. All specialized processes are stored internally in the nomadic router with standard interfaces to the host device and various communication devices.

The nomadic router supports migration to Network Computers by providing identity and security services for the user. The nomadic router also supports multiple parallel communication paths through the communication network for seamless handover processing, increased transfer rate, and fault tolerance by supporting multiple communication substrates.

A portable router that allows a data communication terminal to be transparent in device and location according to the present invention, comprises: a first module to store a digital communication address of a user, a second module to detect a communication network data to which the terminal is connected; a third module for detecting communication devices that are connected to the terminal; a fourth module for establishing data communication between the terminal and the network such that the communication address of the location of the second module is automatically converted to the communication address of the user of the first module; and a fifth module for automatically selecting a communication device that was detected by the third module for use by the fourth module.

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The present nomadic router uses a unique process embodied in a self-contained apparatus that manipulates the data packets that are being sent between the host computers and the routers. This process provides an intelligent active universal translation of the contents of the packets that are being transmitted between the host computer and the nomadic router. Translation allows the host computer to communicate with the nomadic router even when the host computer is not configured to communicate with the nomadic router.

This is accomplished by the nomadic router pretending to be the router the host computer is configured for, and by the nomadic router pretending to be the guest the router expects to communicate with. Therefore, the nomadic router supports the mobility of computers in which it allows these computers to connect to the network in different locations (location independence) without the need to install, configure or use any new protocol on the mobile computer.

The mobile computer continues to operate without realizing the location change or the new configuration, and the nomadic router transmits the data allowing the host to think that it is communicating with the router. By putting this process in a self-contained device, the implementation of new protocols can be carried out independently of the host computer and its operating system (independent of the guest).

All specialized transmissions and processes are stored internally in the nomadic router with standard interfaces to the host device and various communication devices. Therefore, there is no need to adopt new protocols. Eliminating the complexity of supporting different network environments outside of the mobile computer and in this self-contained device, the nomadic router allows the host computer to maintain a minimum set of software protocols and functionality (for example, the minimum functionality that is normally installed on computers network) to communicate over the network.

The transmission ability of the nomadic router also allows the use of alternative communication paths (device independence) without the host computer realizing that some new communication device is employing an alternative communication path. Packet transmission takes place not only at the physical, link or network layer of the protocol stack but also at the transport and application layers. This allows the network card, protocol stack, and application running on the host computer to be independent of the network environment and configuration.

As an example of communication device independence, transmission enables transparent handoff processing, increased transfer rate, and fault tolerance by supporting multiple communication substrates. In addition, the transmitting ability of the nomadic router provides a flexible process for implementing enhanced nomadic and mobile computer software and services such as filtering packets and determining which packets should be allowed to pass between the mobile computer and the nomadic router or network. local area (Internal Firewall).

The router apparatus can be: (i) carried with the mobile user (ie, using an external box); (ii) linked to the mobile computer (eg, PCMCIA card); (iii) installed inside the mobile computer (for example, a chip in the laptop); (iv) installed in the network infrastructure so that it will already be there when the mobile computer user arrives (for example, a box that connects to the local area network transmitting packets that are being sent between the host and the nomadic router , or a chip that is installed in routers on the network). The nomadic router can also be provided in the form of software that loads and works on the mobile computer or another computer or router on a network.

These and other features and advantages of the present invention will be apparent to those skilled in the art from the following detailed description, in conjunction with the accompanying drawings, in which reference numerals refer to like parts.

Brief description of the drawings

Fig. 1 is a diagram illustrating the implementation of the present nomadic router between the host computing device and various communication devices through standard interfaces;

Fig. 2 is a schematic illustrating the basic architecture of the nomadic router, which refers to the hardware implementation architecture;

Fig. 3 is a flow chart showing a configuration overview of the basic steps performed when a host device joins the present nomadic router and when a network interface joins the router;

Fig. 4 is a flow chart showing the automatic adaptation of the router to the host device when the first data packet from the guest is sent to the attached router or when an interrupt or wake-up signal is received;

Fig. 5 is a flow chart showing the process by which the router initializes and checks the various communication device interfaces for initiation, activation, etc;

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Fig. 6 is a schematic illustrating the basic nomadic router architecture when implemented as software in the host device;

Figs. 7a to 7g are diagrams showing protocol stack implementations for various network devices and the transmission function that takes place at all layers of the protocol stack in the nomadic router;

Fig. 8 is a flow chart illustrating the interception of the nomadic router proxy ARP packet and the guest reconfiguration process.

Figs. 9a and 9b in combination constitute a flow chart showing the nomadic router transmission process that takes place in the host computer and nomadic router at various levels in the protocol stack;

Fig. 10 is a diagram illustrating the architecture of the nomadic router implemented as a hardware device that includes a microcontroller and a non-volatile memory for storing algorithms implementing the transmission function;

Fig. 11 is a schematic illustrating the architecture of the nomadic router implemented as an Application Specific Integrated Circuit (ASIC) chip;

Figs. 12a to 12d are schematics showing the nomadic router as implemented in a self-contained box that connects to a local area network via a network interface port and has multiple ports for connecting to host computers;

Fig. 13 is a simplified perspective view showing the nomadic router implemented in a self-contained box that connects to the local area network via a network interface port and has multiple ports for connecting to host computers;

Fig. 14 is a simplified perspective view showing the nomadic router apparatus as implemented in a Type III PCMCIA card where the nomadic router is connected to the type II slot of the host computer and the Type II communication card device connects directly with the nomadic router so that both can be powered and stored in the portable host computer, and

Fig. 15 is a simplified perspective view showing the nomadic router as implemented in a Type II PCMCIA card where the nomadic router connects with the host computer through a Type II interface slot and with the communication card device, Type II, connects to the Type II card of the nomadic router.

Mode (s) for carrying out the invention

Base nomad router

Well-defined standard interfaces

Fig. 1 illustrates a "Nomad" transmitter or router 10 that embodies the present invention by being connected between a host device or computer 12 and a communications device 14. The host device 12 is a laptop or other communication terminal of Fixed or mobile digital data that is portable or mobile enough to be moved from one location to another. A laptop, for example, can be used in any convenient location such as an airplane, a client's office, home, etc.

Communication device 14 can be part of any type of communication system to which host computer 12 can be connected. Such communication systems include, but are not limited to, local networks, wide area networks, direct and telephone internet connections, etc. In a typical application, the communications device will connect to the host computer to a local network that is itself connected to the internet. Therefore, the host device 12 is capable of communicating with an unlimited number of networks and nodes that are themselves interconnected with routers, switches, bridges, etc., in a known manner.

The present router 10 includes a terminal interface 10a that is typically used to connect the router 10 to the host device 12, and a system interface 10b that connects the router 10 to the communications device 14. As will be described below, the router 10 generally includes a processor consisting of hardware and / or software that implements the required functionality. Router 10 is further configured to operate in an alternate mode in which host device 12 connects directly to a network, and router 10 also connects to a point on the network via system interface 10b. In this case, the terminal interface 10a is not used.

Although device 10 is described herein as a router, it will be understood that router 10 is not a conventional router in the sense that it includes the ability to provide interconnectivity between networks. Instead, the present router 10 is essentially a transmitter that allows the host device 12 to automatically and transparently connect to any communications device 14, and process incoming and outgoing data for the host device 12.

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The host device 12 is provided with a permanent internet address that for convenience is not changed in accordance with the present invention. Device 12 is also initially configured to communicate with a home portal or other home device at its home location. The portal has a home address that device 12 attempts to locate when connected to any communication system. Without the functionality of the present nomadic router 10, the host device 12 would be able to operate in a remote location because it would not find its route.

It will be understood that the term "house, landlord" does not refer to a residence, but is the network, portal or other device or communication system to which the terminal is normally connected and that corresponds to the IP address or internet of the house.

Fig. 1 further shows an upper protocol layer 16 that represents the host computing device 12 that generates and consumes information that is transferred via the communications device 14. The interface 16 is made just below the IP layer, and above the link layer in the typical OSI / ISO model. In the middle is a layer 18 that represents router 10 and whose role is to adaptively configure and use the essential communications device and provide the router support described here. A lower layer 20 is a physical communication that carries out the communication (potentially based on a cable Internet, specially designed for a purpose or without cable) causing it to be available and determined for use by the router or nomadic user. Between router layer 18 and layers 16 and 20 there are interfaces 22 and 24 that router 10 identifies and dynamically configures.

This router operates with host computers, routers, and other network devices through well-defined standard interfaces such as those specified by IETF (Internet Engineering Task Force) and IEEE standardization committees. These standards specify the format and content of the package as well as the characteristics of physical communication. As shown in Fig. 7a, the host computers have to be configured in various layers of the protocol stack depending on the communication and configuration capabilities of the current network to which it is being attached.

Hubs, as shown in Fig. 7b, provide a well-defined interface for connecting host computers and network devices by transmitting packets over multiple physical connections. The hubs do not provide any manipulation or translation of the contents of the packets being transmitted.

Jumpers or switches, as shown in Fig. 7C, provide an intelligent filter mechanism by which packets can only be transmitted through multiple physical connection to whose physical connection the device is connected, according to the address of link layer (Media Access Control Address). Bridges and switches do not manipulate the contents of the packet and do not provide greater functionality to the layering protocol.

Routers, as shown in Fig. 7d, accept packets based on the destination address at the network layer in the packet. The host computer must explicitly direct the packet at the link layer to the router. The router will then transmit the packet over the correct physical connection based on which it is configured. No modification or translation of the packet is performed at any layer of the protocol stack other than at the network layer.

Firewalls, as shown in Fig. 7e, filter packets on the network and transport layers to allow only certain packets to be transmitted to the other physical connection. Firewalls do not manipulate the content of the packet, they only send it to the next hop on the network if it passes the transport (port) or network (IP address) filter.

Proxies and routes, as shown in Fig. 7f, only receive packets explicitly addressed to them by host computers. They only handle packages at the application level. The present nomadic router 10, as shown in Fig. 7g, manipulates the content of packets at the link, network and application layers of the protocol stack to provide a transmission between the mode in which the host computer is configured and the network configuration to which the host computer is the one that is currently connected.

Unlike all the devices shown in Figs. 7a to 7g, router 10 will automatically intercept and transmit packets without other devices noticing or having been configured to use router 10. The transmission algorithms on router 10 that provide this location independence are provided entirely internal to router 10. Therefore, no new guidelines need to be developed, accepted, or implemented in host computers 12 or routers 26 to bring new network services into operation when using the nomadic router.

Whenever a new or different communication device (including the link and physical layers) is used in a host computer 12, the host computer's network layer must perceive this new communication device. Because router 10 has its own communication interface with the communication device, alternate communication devices can be used on router 10 that the host computer 12 can use but need not be configured for.

Permanent Addresses Not Based on Location

Today we communicate with individuals in terms of the location of their communication tools (for example, their computer IP address or their fax number). In order to support environments and devices

ES 2 290 986 T3 communication in change and mobility, it is necessary to create an environment where people communicate with each other, and not specifically with the devices they use. To transparently support mobility and adaptability in a potentially appropriate wireless communications network, a common virtual network must be provided by an intelligent device or agent that supports the different host computers and communication devices.

The present nomadic router 10 provides the links between the location-based IP address used today on the internet and the permanent address of the user housed in the guest CPU in the device 12. This is illustrated in Fig. 2 as "IP Links". These links are made without the support or knowledge of such links by the guest CPU or user.

The Internet Protocol RFC 2002 Mobile IP specifies the links between permanent and temporary IP addresses. The only aspect of the nomadic router is that the Mobile IP protocols do not necessarily work on, or are not supported by, the host CPU but are internal to the nomadic router. The host's configuration information such as its IP number are discovered or determined as illustrated in Fig. 4 and stored in the nomadic router 10 as illustrated in Fig. 2, as "Guest Info". The configuration process is generally observed in Fig. 3.

Optional Download Process

As shown in Fig. 2, the nomadic router 10 can provide offload communication processes for the host CPU by physically separating itself from the host device 12. The adaptation, selection, and transport of information through the network is performed by part of the nomadic router 10. This allows the host terminal or device 12 to use the network without having to directly support network protocols. With the nomadic router being responsible for adapting to the current network substrate, the guest CPU can maintain high performance by not having to perform routing, adapt and pack algorithms, or process packets.

The nomadic router can also queue, transmit and receive information regardless of whether the host device 12 is available and even connected. The CPU 11 built into the nomadic router 10 provides all the necessary computing routines to be a fully functional network coprocessor independent of the guest CPU. This will allow increased battery life for the user since the nomadic router does not have as many user I / O devices as the host device 12 does.

Location Independence

The nomadic instant network router provides the ability to provide ubiquitous and reliable support in a location independent mode. This removes all weight on the user for device configuration (for example, IP address configuration, next-hop router or route address, netmask, link-level parameters, and security permissions) or information transmission.

The problem with existing protocol stacks is that communicating devices have to be reconfigured every time the communication environment changes. TCP / IP requires a new network, node, and route number. Appletalk will automatically choose an unused node number and discover the network number, but all open communications are lost and services have to be restarted to start using the new information.

This occurs, for example, when a PowerBook connects to one network, hibernates, and then connects to a different network. All network services restart after waking up, and network applications get confused if they are not restarted. The nomadic router solves this problem by providing temporary as well as permanent network and node numbers similar to those provided by Mobile IP. However, the nomadic router will also work with other protocol stacks (eg AppleTalk).

Mobile IP provides location independence at the network level and not at the link level. All link level parameters, which are device specific, will be automatically configured as shown in Fig. 5 when a new communication device (network interface) connects to the nomadic router. The nomadic router completely eliminates the need for manual configuration by supporting tailored device independence.

Multiple Substrates (Device Independence)

Another innovative feature of the nomad router is the support of multiple communication substrates for simultaneous use. This is illustrated in FIGL 2 as "Device Selection". Users should be able to use two or more communication substrates, either to increase the transfer rate or to provide capacity in the transparent transfer process. This functionality is not supported in today's typical protocol stacks (eg TCP / IP or AppleTalk).

For example, through the “network” control panel, the user can select from communication substrates such as EtherTalk, LocalTalk, Wireless, ARA, etc., but cannot remotely register to EtherTalk while trying to print via LocalTalk. Routers are typically capable of joining multiple communication substrates, but merging the LocalTalk and EtherTalk networks is often undesirable for several reasons, including performance and security.

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One problem with existing routers today is that they require manual configuration and outputs external to the node. To overcome this, the nomadic router can support the automatic configuration and full functionality of the router internally. This allows a nomadic or mobile node to adapt to various network and communication devices dynamically, such as when the user connects a PCMCIA card or connects a communication device to the serial port.

Once the nomadic router senses the available communication devices and activates them, data transport takes place across the multiple communication substrates. The only algorithm and protocol in the nomadic router that chooses the most suitable device for use is shown in Fig. 2 and Fig. 5 as part of the “Nomad Router Device Checker” through the “Nomad Router Device Selection” throughout each interface.

There are numerous factors that can affect the selection of use of one or more devices. Such factors typically include available bandwidth, cost to start and maintain the connection, power or power requirements and availability, and user preferences.

Another feature of the nomadic router is the support of alternate or simultaneous use of several communication substrates. This is done as part of step 5 in Fig. 6 when the source address is that of the communication substrate where the nomadic router is going to send the packet. Now, host computers will indirectly be able to use two or more communication substrates, either to increase the transfer rate or to provide capacity in the transparent transfer process.

This functionality is not supported in today's typical protocol stacks (eg TCP / IP or AppleTalk). Once the nomadic router senses the available communication devices and activates them, data transport takes place across the multiple communication substrates. The only algorithm and protocol in the nomadic router that chooses the most suitable device for use is part of the "Nomadic Router Device Checker" through the "Nomadic Router Device Selection" across each interface.

There are numerous factors that can affect the selection of use of one or more devices. Such factors typically include available bandwidth, cost to start and maintain the connection, power or power requirements and availability, and user preferences.

Hardware specification

The nomadic router can run entirely in software without any special hardware as shown in Fig. 6, or without a separate CPU from the main host, or packaged as a hardware device as shown in Fig. 2. The Nomadic router can also be provided as a digital storage medium that stores the software program that implements the router's transmission processing functionality. Examples of digital storage media include optical media (eg, CD-ROM), magnetic media (eg, 3 1/2 disk), non-volatile or read-only memories, or any combination thereof. The program is loaded and runs on the mobile terminal 12, or alternatively on any other computer or router that is connected to the network.

One potential implementation of the nomadic router device is Integrated PC Technology. As an example, the standard rugged PC / 104 modules have a 3.550 ”form factor and typically 0.6” per module and weigh approximately 7 oz. By module. Using the PC / 104 module is a self-accumulating bus with minimal component count and power consumption (typically 1-2 Watts per module) eliminates the need for a rigid card cage or backplane.

The nomadic router can run on a 16-bit bus with an 80486 processor, for example. Standard network access devices can support boot rates of up to 10 Mbpps with typical user data transfer rate around 1-2 Mbps. Bandwidth is lower depending on the wireless communication device available. For example, Proxim's 2 Mbps wireless LAN typically covers 500 yards with typical user data transfer rate around 500 Kbps. As shown in Fig. 1, the nomadic router typically includes 3 modules; a processor 10, host device or terminal interface 10a, and communication device or system interface 10b.

Another potential hardware implementation is with CARDIO S-MOS System Technology. This CPU motherboard is basically the same size as a PCMCIA credit card adapter. It is 3.55 X 3.775 X 0.6 inches. Power requirements are + 5V DC +/- 10% with an operating temperature of 0 to 70 ° C, a storage temperature of -40 to 85 ° C, and a relative humidity of 10% to 85% non-condensing.

The CARDIO is the most compact PC / 104 compatible system available that meets the mechanical and electrical specifications of a PC / 104 Rev. 2.2 battery. Power failure indicator, battery backup and automatic shutdown are also possible.

The nomadic router can also be implemented in a small portable device such as a PCMCIA card or partially in a PCMCIA card. In the case of a full implementation on a PCMCIA card, the host CPU and power supply are used to run the Nomad Path and other protocols, algorithms, systems

ES 2 290 986 T3 operational, and application services. A hybrid implementation of part of the PCMCIA card and part of other hardware can also be used.

Apparatus Components

When transmitting packets in a self-contained device, the process carried out on the packets in the nomadic router does not affect and is downloaded from the host computer. All the specific transmission of the packets to fit with the configuration and available network services is carried out internally to the nomadic router. The nomadic router can queue, transmit and receive data regardless of whether its host computer is available or even connected. The algorithms and microcontroller built into the nomadic router provide all the computational routines necessary to be a fully functional network coprocessor independent of the host computer.

By allowing the nomadic router to process packets independently of the host computer, the host computer can be shut down or hibernated while the process takes place, providing increased battery life for the host mobile computer.

The nomadic router can be configured with various components in various ways. In Fig. 10, the nomadic router contains a processor or microcontroller 11 to transmit the packets stored in packet buffers in arbitrary access memory. The transmission functions are stored in non-volatile memory 13 with the Real Time Operating System (SOTR) and the configuration information on the types of transmission that need to be performed.

Upon startup of the nomadic router, the SOTR and transmission algorithms are downloaded from the non-volatile memory in RAM from where they run. There can be zero, one, or more guest interfaces to which the guest computers connect. There are one or more network interfaces. If no guest interface is available, then the nomadic router picks up the packets via the host computer from the network interface.

In Fig. 11, the nomadic router 10 is implemented as an Application Specific Integrated Circuit (ASIC) or Programmable Gate Array (FPGA) 15. These chips integrate the algorithms for packet transmission. The chip may include storage for non-volatile memory 17 which stores configuration information as when it was manually configured for the current network. Chip 15 can also include arbitrary access memory to buffer packets for transmission on the nomadic router prior to forwarding to the host or network interface.

Apparatus Packaging

As described above, the nomadic router can be packaged in different hardware configurations. The nomadic router can be integrated into the host computer, or network device such as a switch or router. It can also be implemented as a PCMCIA card that connects to the host computer or a self-contained external box.

Each nomadic router can have one to many interfaces. If the router 10 is put into the network infrastructure, the mobile user does not have to carry it with him. As shown in Fig. 12a, nomadic router 10 is connected to a Local Area Network (LAN) of the network infrastructure that constitutes communication device 14 through system interface 10b. LAN 14 is connected via a conventional router 26 to the internet 28. In this case, the host computer interface 10a of the nomadic router 10 is not necessary since the packets of the host computer 12 are received via LAN 14.

To provide a secure interface between host computer 12 and network 14 to prevent host computers 12 from being able to see (sniff) packets on network 14, nomadic router 10 may interface with host computer 12 (terminal interface (10a) and a second interface (10b) to network 14 as shown in Fig. 12b, and provide packet filtering and relay between the different interfaces thereby providing a firewall type of security device that operates internally on the network.

In order to support multiple guest computers 12a ... 12n with a single nomadic router 10, the nomadic router 10 can have multiple guest interfaces 10ai ... 10a_n as shown in Fig. 12C and Fig. 13 and a network or system interface 10b.

If the nomadic router is carried by the mobile user, it can take the form of a PCMCIA card. In Fig. 12d, the nomadic router 10 is implemented as a PCMCIA card. The storage and transmission capacity is stored inside the card and the interface of the host computer 12 is found through a PCMCIA BUS interface or communication card 30.

As shown in Fig. 14, the PCMCIA card can fit into a type III slot where there is a connector on the nomadic router 10 that accepts communication card 30 (a type II PCMCIA card). In this way, the nomadic router does not have to have the specific communication device components inside the PCMCIA card.

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The nomadic router 10 can also take the form of a type II PCMCIA card. In this way, the communication device or card 30 is connected to the opposite end of the nomadic router card 10 as shown in Fig. 15.

Nomad Router Broadcast Operation

Initialization and Self-configuration

The nomadic router initiation and autoconfiguration process provides the means by which the nomadic router is able to learn about the host computer and network so that it knows what transmission is necessary. Guest Learning

The nomadic router 10 is able to learn how the host computer 12 is configured by looking at the content of the packets that are being sent from the host computer 12. Rather than the host computer 12 sending packets directly to the router 26 or other network device, to What is initially configured, the nomadic router 10 is able to redirect all the outgoing packets from the host computer 12 to itself. This redirection can be carried out in different ways as described below:

1. ARP Proxy Packet Interception and Host Reconfiguration

Whenever a host computer 12 has an IP packet that needs to be sent to a router 26 or other network device, it uses the Address Resolution Protocol (ARP) to obtain the link layer address of Media Access Control (address MAC). As shown in Fig. 8, when the host computer 12 transmits an ARP request for the MAC address of a destination node, the nomadic router 10 receives this ARP request transmission and responds with its MAC address (not that of the destination node).

When the host computer 12 receives this ARP response from the nomadic router 10, which contains the MAC address of the router 10, the host computer 12 will store this MAC address in the host computer 12 and send all the packets destined for the configured router or network device. to the nomadic router 10. The host computer 12 will think that the MAC address is that of the configured IP network device, but in reality the nomadic router 10 is pretending (representing) to be the device (its home route) that the host computer 12 hopes to find.

The nomadic router 10 is also capable of reconfiguring and intercepting return packets from a router or other network device using the same process.

2. Promiscuous Mode Packet Interception

Because the MAC address is stored in the host computer 12 for a short period of time, the host computer 12 will not issue a new ARP request to obtain the MAC address again unless a period of disconnection occurs or the reservation disappears. like when computer 12 reboots.

When a conventional network device 12 receives and hears a packet with a MAC address that does not match its own, it will ignore or abandon the packet. Because it is possible to quickly switch from one network environment to another using a laptop, the nomadic route 10 must be able to intercept packets even when the MAC address is not that of the home device or route of the nomadic router.

This is achieved by placing the network connection of the nomadic router in a promiscuous way. In this way, the network connection in the nomadic router accepts all the packets that are being transmitted on the communication link, not just the ones that are being transmitted or directed specifically to it.

3. Dynamic Host Configuration Protocol (DHCP) service

A host computer is able to use the DHCP service to obtain configuration information instead of being manually configured. The host computer using the DHCP service requires a DHCP server to be installed on the network segment to which it is currently connected. If the host computer is using this service and requests the configuration information using DHCP, the nomadic router 10 will intercept these requests and respond with configuration information for the host computer 12 to use.

Network Learning

The nomadic router is able to learn about the network environment to which they are currently connected using different methods such as those described below.

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1. Dynamic Host Configuration Protocol (DHCP)

Whenever a different network connection is connected to the nomadic router, it will transmit a DHCP request to obtain configuration information for the current network. If no DHCP service is available on the network, you will switch to another method to learn about network settings.

2. Router Information Packets

Routers on the network will periodically transmit packets of router information that are used to build route tables and allow routers to adapt to changes in the network. Nomadic router 10 will listen on the network for these router information packets. When one is received, it will extract the configuration information from these packets.

3. Passive listening

By placing the network connection of the nomadic router in a promiscuous way, where all packets are received and not just those destined for it, it is also able to examine all the packets on the network and find out how the network is configured. It is also able to determine the IP addresses used in the local area network and whose machines are routers by the final destination address that is not the next hop address.

Using this method, the nomadic router 10 is passively able to learn how the network is configured and will choose to use an unused IP address. If that IP address is used by another network device, it will change to another unused IP address.

Four. Manual Configuration

Network configuration information can be manually configured on the nomadic router 10. This information can be set using a built-in network server, Simple Network Management Protocol (SNMP) tools, an application running on one of the computers on the network , or other suitable means. When manual configuration is used to set the network information, the nomadic router 10 will continue to automatically learn about the host information and provide all the transmission skills so that the host computers do not have to realize the correct network information. LAN to which they are currently connected.

Package Transmission

The packet forwarding function of the nomadic router provides a link between the location dependent service configuration employed by the host computer 12 and that is employed by the network 14 to which it is currently connected. For outbound traffic from host computer 12 to network 14, the transmission function changes packet content such as source address, checksum, and application-specific parameters, causing all packets to be broadcast to the network. 14 go back to nomadic router 10 instead of host computer 12.

Incoming traffic from the network 14 that reaches the nomadic router 10, which is actually for the host computer 12, goes through the broadcast function so that the host computer 12 thinks that the responses were sent directly to it. The host computer 12 will not perceive at all all the transmission that is being carried out by the nomadic router 10.

The transmission functions work as shown in Figs. 9a and 9b. In these figures, operations performed at the application, transport, network, link, and physical layers of the OSI / ISO model are illustrated by arrows opposite the layer designations. The operations performed by the host computer 12, the nomadic router 10, and the network 14 are illustrated in columns below the device designations.

The host computer 12 will generate network packets using the current configuration stored in the host computer using the standard protocol stack shown in Fig. 1. This configuration information is either manually configured in the host computer 12 or obtained using DHCP.

As shown in step 2, when the host computer 12 directs the link level destination address, the address automatically obtained using the Proxy ARP packet interception routine described above, this will cause the host computer 12 to send the packet to the network address of your router or standard home route device, but using the link level address of the nomadic router 10.

In step 3, the packet is transmitted over the standard physical connection between the host computer 12 and the nomadic router 10. As shown in step 4, the nomadic router 10 will receive the packet at the link level fine due to the Proxy ARP function that reconfigured the host computer's MAC address, or the nomadic router 10 will have the link level in promiscuous mode which will cause it to receive the packet even if it goes to a different MAC address.

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Once the packet passes to the network layer, as shown in step 5, the transmitting function of the nomadic router will modify the contents of the packet to change the source address to be equal to that of the nomadic router address. instead of the address of the host computer. It will also transmit other location-dependent information such as the name of the local Domain Name Service (DNS) server. When the DNS packet is transmitted, it will change the source address to that of the nomadic router address and the destination address to that of a local DNS server.

Once the network layer transmission is complete, the packet can be transmitted in the application and in the transport layers. The application layer is subsequently transmitted, as shown in step 6, because the transport layer needs a network layer pseudo-header that includes the source and destination addresses and the content of the application layer.

In application layer transmission, any address that describes the host computer's source address, as with FTP, is translated to be the address of the nomadic router. Any destination address in the application layer, such as a local proxy server, is translated to be the same as the server operating on the current network.

Once the application transmission is complete, the transport layer, as shown in step 7, can complete the checksum and any port number manipulations. The port number is manipulated if more than one host computer 12 is connected to the nomadic router 10. Each host computer 12 when sending a request using a specific port is moved to match an available inbound port on the nomadic router 10.

The port number assigned for use with each host computer 12 is stored in a table in the nomadic router 10 and is used with the response packet described later. Finally, the packet is sent to network 14 in step 8.

When a reply packet comes in from network 14, as shown in step 9, nomadic router 10 will receive the packet. In step 10, the nomadic router will perform the inverse network layer translation to set the destination address with that of the host computer 12 instead of with the address of the nomadic router, and any source address with the one replaced by the nomadic router 10 in step 5.

Once this network transmission is complete, the packet is transmitted to the application layer, as shown in step 11, to change the destination address to that of the host computer 12 and the source address to the destination address. original stored in step 6. In step 12, any port manipulation performed in step 7 is changed to the original setting and a new checksum is computed. Finally, as shown in step 13, the packet is sent to host computer 12 which then processes the packet manually.

Nomad Router Options

There are numerous options and applications of the nomadic router. These applications include, but are not limited to, Nomadic Email, Remote Network File Synchronization, Nomadic Database Synchronization, Instant Network Nomad Route, Nomadic Intranets, Trade Show Data Exchange. Each of these applications is described in more detail below:

Nomad Email

Nomad Email provides a distributed and synchronized mode for updates, reconciliation, and replicas that propagate across the internet. In various locations on the internet there are nomadic routers equipped with email support that provides the necessary synchronization, etc. Each nomadic router allowed to have nomadic email can use special protocols like IMAP that provide support for mobile users without the host computer having to support it (as is now the case with the standard POP3 protocol in most email clients in Internet).

Remote Network File Synchronizer

The nomadic router's Remote Network File Synchronization option provides copies of user files stored / saved in various locations (eg hotel, office, home) on other nomadic routers equipped for remote network file synchronization. Copies of up-to-date records are automatically synced and distributed between all the same or even locations. Local updates can be done while the guest is disconnected from the nomadic router and the network.

Nomadic Database Synchronizer

The Nomadic Database Synchronizer hosts the user's master databases (synchronized) (eg, contacts, addresses, phone numbers). The nomadic router of the synchronizer does not even need to be used in the network as it will interact directly with various host devices such as laptops, computers

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Nomadic Instant Network Router

The objective of the Instant Network nomadic router is to be able to set up a communication network in any environment with little infrastructure or with no fixed infrastructure. Host and communication devices do not have to directly support Quick Start functionality.

Smart Distributed Instant Network Nomad Router establishes a wireless (or wired) communication link between the host device and the desired communication system while performing configuration, multi-hop and security path, and layer data transmission network over various communication devices. The nomadic router performs all necessary network creation and processes automatically to remove configuration and system support from the guest or user system. The Instant Network Nomad Router uses proprietary and existing / emerging wireless communication systems and multi-hop path protocols.

As a mode of innovation, many communication infrastructures are varied and fragmented, and this problem may get worse as more technologies are introduced. For example, high performance LANs, wireless services, cellular telephony, satellite, ubiquitous paging networks, provide various degrees of coverage, cost characteristics, and bandwidth / delay.

Sometimes, there will be no connectivity at all due to lack of service, there will be partial or intermittent connectivity when devices connect and disconnect from a system, damage to communication infrastructures deliberately or by accident, unstable communication when a system moves through multiple service areas or difficult domains, and occasions when multiple network devices (communication substrates) can be used at the same time. The nomadic instantaneous network router will dynamically adapt the communication network, dynamically creating one if necessary, to provide communication capable of surviving in a chaotic mobile environment without the need for centralized control or fixed infrastructures.

The nomadic router that gets up and running is a device choked with every user host device (for example, PDA or laptop). It transparently provides capabilities for host computer systems that use multiple wireless communication devices for link and physical layer access.

1. Dynamic wireless network creation.

2. Initialization in existing wireless networks.

3. Automatic configuration.

Four. Network and subnet level data transmission.

5. Multi-hop route functionality.

The nomadic router can detect a device that is being used either by scanning the interface, providing an interrupt signal, or by means of specialized signals. This in turn enables the nomadic router to configure the device (if necessary) and establish a communication link with a corresponding and appropriate interface and wireless subnet. The nomadic router operates at a level between the host device that generates the data and the physical communication transmission device as shown in Fig. 1.

Nomad Intranet

The Nomad Intranet provides all the services, server types and networks for users to dynamically create an appropriate network. This is similar to the instant network nomadic router except that the nomadic intranet is a single device with multiple ports on which laptops / devices can connect. The instant network nomadic router is distributed to (one for) each host device. The nomadic intranet not only provides appropriate networks but also provides services such as file buffering, protocol conversion, acts as a recording server, and provides other services described as part of the basic nomadic router.

Nomad Router for Trade Show

The Nomadic Trade Show Router not only provides the basic nomadic router functionality for an exhibitor computer that is brought to the exhibition, but also provides a primary mechanism for capturing and / or distributing information. The main fetch mechanism can be provided by interacting with a badge reader to read the information from the wizard. This information is then captured by the nomadic router and made available in the exhibitor's main database.

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The nomadic router can also provide a mechanism for the distribution of information to the personalized web page of the wizard or send via e-mail over the internet. The exhibitor's computer is capable of controlling the flow of information with the nomadic router by running software, such as a browser, that talks to the service / control software stored in the nomadic router. The standard web browser can control the display and capture of main information, collection of required information, and selection of information to be distributed back to the wizard.

Fixed Nomad Router

The Fixed Nomad Router provides the same basic functionality and architecture as the Portable Nomad Router but is stored in one location. The fixed nomadic router acts as a surrogate or "Home Agent" for the user when he / she is away on the road. When the user wants to register or use his host device somewhere else on the network, the portable nomadic router will register with the fixed nomadic router where it is temporarily connected to the network so that the information can be sent to the user's new location. The fixed nomadic router can be used to host the master copy of the user's email for the nomadic email service, or files for the nomadic file synchronizer.

Mobile Virtual Private Network

The nomadic router provides the link between the location-based IP address used on the internet today and the permanent user-based address hosted on the guest CPU. This link is made without support or knowledge of such link by the guest or user CPU. The Internet protocol RFC 2002 Mobile IP specifies the link between permanent and temporary IP addresses. The only aspect of the nomadic router is that the Mobile IP protocols do not necessarily work on, or are not supported by, the host CPU but are internal to the nomadic router.

By implementing this protocol as part of the transmission function in the nomadic router, the nomadic router can encapsulate packets from the host computer and transmit them back to the fixed nomadic router that are sent (not encapsulated) on the native (home) network. Responses are received from the home network by the fixed nomadic router and encapsulated and returned to the nomadic router. When packets are transmitted between the nomadic router and the fixed nomadic router, the packets are encrypted and sent using the Internet Construction Protocol.

Because the nomadic router provides location independence and the fixed nomadic router sends all packets from a corresponding host to the host computer through the nomadic router, any change in location, failure of a network link, or endpoint of the mobile host computer does not cause any open session to be lost. This prevention of session loss is possible as the fixed nomadic router pretends to be the mobile host computer, and the nomadic router pretends to be the home network. The functions of the fixed nomadic router and the nomadic router transmission hide the link and network loss of the transport and application session.

For those skilled in the art, various modifications will be possible upon receipt of the guidelines of the present disclosure without departing from the scope thereof.

Industrial applicability

The present invention is widely applicable to the field of electronic information communications using computers and other devices.