A) TECHNICAL FIELD
[0001] The present invention generally relates to a network communication systems and particularly to gateway devices for communication networks like ZigBee networks, controller area networks (CAN), etc. The present invention is more particularly relates to gate way devices for communication between wired and wireless networks in automotive applications.
B) BACKGROUND OF THE INVENTION
[0002] Automation is the use of control systems such as computers to control mdustrial machinery and industrial processes thereby reducing the need for human intervention. The ability to control one or more devices based on one or more parameters is known as automation. Automation can be implemented in different areas such as automobiles, buildings, offices, industries, stores, restaurants etc. Automation can be implemented using extensive computer networks. Computer networks are known in which a computer issues a series of commands over an Ethernet network to an output devices. The commands are complex data structures requiring the computer to establish a communication protocol between the server and computer transmitting multiple data packets.
[0003] The most prominent automotive applications use networks such as Controller Area Network (CAN), Vehicle Area network (VAN) etc for interconnecting different nodes. It can be used in real-time applications. Advanced electronic systems in automobiles such as power steering, fuel injection and power locks operate on a

controller area network (CAN). The CAN is a computer network protocol and bus standard designed to allow micro controller and devices to communicate with each other without a host computer. This well-developed wired network allows efficient communication between the sensors and actuators of each device. However this network fails, when the wires cormecting devices sustain damage. One solution is to design an entirely new communication system that uses wireless commimication. This is not a viable or practical solution because of the large amounts of capital invested by automobile manufacturers in the development of the CAN system. A more feasible solution is to design a new system around the CAN protocol by adding a gateway that changes wired signals mto wireless signals.
[0004] ZigBee is a low-cost, low-power wireless communications solution, meant to be integrated as the main building block of ubiquitous networks. It is a high level communication protocol using small, low-power digital radios based on the IEEE 802.15.4-2006 standard for Wireless personal Area Networks (WPAN). The technology is intended to be simpler and cheaper than other networks like Bluetooth. ZigBee is targeted at radio frequency applications that require a low data rate, long battery life and secure networking. The low cost allows the technology to be widely deployed in wireless control and monitoring applications. The low power usage allows longer life with smaller batteries. The mesh networking in the ZigBee provides higher reliability and larger range. ZigBee provides facilities for carrying out secure communications, protecting establishment and transport of cryptographic keys, ciphering frames and controlling devices.

[0005] Incidentally, the term "ZigBee" originates from the silent, but powerful method of communication used by honeybees to report information about food sources. This communication system is known as the "ZigBee Principle". By "dancing" around in a zigzag manner, a bee is able to share critical information, such as the location, distance, and direction of a newly discovered food source to its fellow hive members. [0006] The CAN and ZigBee protocols are used in mutually different automotive applications. The two protocols are used in different products separately in different applications.
[0007] The prior art patent No. US72I1968 discloses a Remote lighting control system for building automation network. It includes a processor to generate electronic control signals identifying ballast control points corresponding to instructions received at wireless interface. It discloses that a CAN bus may be unplemented in the building automation network or other suitable wireless protocol.
[0008] The prior art patent No. US20060271204A1 discloses a building automation system with hot reprogramming of building automation devices. The automation system utilizes a CAN bus for conmiunication. It also discloses that other networks such as Bluetooth and ZigBee can also be used.
[0009] None of the currentiy available systems provides a facility for integrating both the CAN and ZigBee protocols into a single unit which may be used in automotive applications. More over none of the currently available systems in automotive applications is able to convert the wired protocol into a wireless protocol and vice versa.

[0010] Hence there is a need to develop a gateway to send CAN signals over a wireless medium and to convert the CAN packets into wireless packets and vice versa. Also there is a need to develop a single unit which may be operated in both the CAN and ZigBee protocols.
C) OBJECTS OF THE INVENTION
[0011] The primary object of the present mvention is to develop a gateway system to send CAN signals over a wireless medium in automotive applications.
[0012] Another object of the present invention is to develop a gateway system in which both the CAN and ZigBee protocols are integrated together to convert the CAN packets into wireless packets and vice versa.
[0013] Yet another object of the present invention is to develop a gateway system to transmit the CAN signals over Zigbee network and to transmit the wireless signals through CAN network in automotive applications.
[0014] Yet another object of the present invention is to develop a reliable, highly secure gateway system for the CAN and Zigbee communication networks in automotive applications.
[0015] Yet another object of the present invention is to develop a gateway System with flexible interface for CAN and ZigBee communication networks.

[0016] Yet another object of the present invention is to develop a gateway system with low power consumption for CAN and ZigBee communication networks.
[0017] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
D) SUMMARY OF THE INVENTION
[0018] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
[0019] The various embodiments of the present invention provides a gateway system and method to interface both the CAN and ZigBee networks m automotive applications to transmit the CAN packets through ZigBee Networks and to transmit the wireless packets over the CAN.
[0020] According to one embodiment of the present invention, the gateway system has a gateway unit provided with both CAN and ZigBee interfaces and RP transceivers. The gateway unit may act as a coordinator or reduced function device. The gateway unit has a microcontroller to regulate the operation of a radio frequency (RF) transceiver to transmit and receive CAN signals through Zigbee network. The gateway unit may act as a full fimction device to provide an interface between the CAN and ZigBee network. The data received through CAN bus is transmitted through

ZigBee network and vice versa. The gateway unit may act as a reduced function device to receive data from sensors or vehicle diagnostic tool or from different vehicle buses through CAN bus and to transmit the received data through RF transceiver to ZigBee network. The gate way unit may be programmed to act as a full function device (coordinator) or as a reduced function device. Software is loaded into the gateway unit to act as a full function device or reduced function device.
[0021] According to another embodunent of the present invention, the gateway system has a coordinator or full function device, routers and reduced function device (RFD). The gateway system is employed to connect the multiple electronic control units to multiple sensors using a single vehicle CAN bus. The RFD receives the input from the sensors and transmits the received sensor input to coordinator through ZigBee network. The data received from the RFD is sent to the respective Electronic Control Units (ECU) through a single vehicle CAN bus by the coordinator over a CAN bus.
[0022] According to another embodiment of the present invention, a gate way device is used to transmit the data from the multiple vehicles to a single coordinator through CAN and Zigbee protocols. The input data from the multiple vehicles are passed through the multiple vehicle CAN buses. The data passed through the multiple vehicle CAN buses are transmitted over the respective CAN buses to the multiple RFDs. The lata received at the RFDs are transmitted to a coordinator through a Zigbee communication protocol for processing. The received data are processed for the next stage based on the application.

[0023] According to another embodiment of the present invention, a gateway system is used to transmit data to ECU m remote vehicle diagnostics system. The RFD is comiected to a vehicle diagnostic tool through a CAN bus. The input received from the vehicle diagnostic tool is sent to a coordinator through ZigBee communication network by the reduced function device. The data received at the coordinator is sent to the ECU through CAN bus and vehicle CAN bus.
[0024] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0026] FIGURE. 1 shows a block diagram of a gateway system according to one embodiment of the invention.
[0027] FIGURE.2 shows a block diagram of a gateway system used for transmitting the outputs of multiple sensors to multiple ECUs through single vehicle CAN bus, according to one embodbnent of the present mvention.

[0028] FIGURE.3 shows a block diagram of a gateway system used for transmitting the data from the multiple buses to a single coordinator through multiple vehicle CAN buses and RFDs, according to one embodiment of the present invention.
[0029] FIGURE.4 shows a block diagram of a gateway system used for transmitting data in remote vehicle diagnostic system.
[0030] Although specific features of the present invention are shown m some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
F) DETAILED DESCRIPTION OF THE INVENTION
[0031] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0032] The various embodiments of the present invention provides a gateway system and method to interface both the CAN and ZigBee networks in automotive

applications to transmit the CAN packets through ZigBee Networks and to transmit the wireless packets over the CAN.
[0033] According to one embodiment of the present invention, the gateway system has a gate way unit provided with both CAN and ZigBee interfaces and RF transceiver. The gateway unit may be a coordinator or reduced function device. The gateway unit has a buiU in microcontroller to regulate the operation of a radio frequency (RF) transceiver to transmit and receive CAN signals through Zigbee network. The micro controller may regulate a radio frequency transceiver to receive wireless signals transmitted through the ZigBee network and to transmit the received sigials through CAN bus. The gateway unit may act as a full function device to provide an interface between the CAN and ZigBee network. The data received through CAN bus is transmitted through ZigBee network and vice versa The gate way unit may act as a reduced function device to receive data from sensors or vehicle diagnostic tool or from different vehicle buses through CAN bus and to transmit the received data through RF transceiver to ZigBee network. The gateway xmit may be programmed to act as a full function device or as a reduced function device. Software is loaded into the gate way unit to act as a full function device or reduced function device. The full function devices have the resources to perform more complex task such as coordmator or Router but can also be an End Device in a network. The reduced function devices are reduced complexity nodes with relatively limited memory, processing, and power capabilities. They can only serve as End Devices in a network and cannot perform the more complex roles of Router or Coordinator.

[0034] According to another embodiment of the present invention, tiie gateway system has a coordinator or full function device, routers and reduced function device (RFD). The gateway system is employed to connect the multiple electronic control units (ECU) to multiple sensors using a single vehicle CAN bus. The sensor out put data may be a tyre pressure data, wheel alignment data, the speed value, collision data etc. The RFD receives the input from the sensors and regulates RF transceiver to transmit the received sensor input to coordinator through ZigBee network. The coordinator regulates RF transceiver to receive the wireless data transmitted over the ZigBee network from the RFD. Multiple ECUs are connected to the single vehicle CAN bus which is in turn connected to the coordinator through a CAN bus. The built in microcontroller in the coordinator regulates the RF transceiver to pass the received sensor data to the respective control units through the CAN bus and the single vehicle CAN bus. Thus the data received from the RFD is sent to the respective electronic control units (ECU) through a smgle vehicle CAN bus by the coordinator over a CAN bus.
[0035] According to another embodiment of the present mvention, a gate way device is used to transmit the data from the multiple vehicles to a single coordinator through CAN and Zigbee protocols. Multiple ECUs are connected to respective vehicle CAN buses which are connected to the multiple RFDs through respective CAN buses. The input data from the multiple vehicles are passed through the multiple vehicle CAN buses. The data passed through the multiple vehicle CAN buses are transmitted over the respective CAN buses to the multiple RFDs. The microcontroller in the RFD regulates the RF transeivers to receive the data transmitted through the CAN buses and to transmit the received data through ZigBee network to the coordinator. The

microcontroller in the coordinator controls the RF transceiver to receive the data transmitted ftom the RFDs through ZigBee network. The received data are processed in the coordinator for the next stage based on the application. The processed result is cUsplayed on a screen.
[0036] According to another embodiment of the present invention, a gateway system is used to transmit data to ECU m remote vehicle diagnostics system. The RFD is connected to a vehicle diagnostic tool through a CAN bus. The buih in microcontroller in the RFD regulates the RF transceiver to receive the data sent from the vehicle diagnostic tool through the CAN bus. The input received from the vehicle diagnostic tool is sent to a coordinator through ZigBee communication network by the reduced fimction device. The microcontroller in the RFD controls the RF transceiver to transmit the received vehicle diagnostic data to the coordinator through the ZigBee network. Muhiple ECUs are connected to a single vehicle bus which is in turn connected to the coordinator through CAN bus. The data received at the coordinator is sent to the respective ECU through CAN bus and vehicle CAN bus. The coordinator regulates the RF transceiver to receive the data transmitted through the ZigBee network from the RFD and to transmit the data to the ECU through CAN bus and vehicle CAN bus.
[0037] FIGURE.l shows a block diagram of a gateway system according to one embodiment of the invention. With respect to FIG.l, the gateway system has a gate way unit provided with both CAN and ZigBee interfaces and RF transceivers. The gate way unit may act as a coordinator or reduced fimction device. The gate way unit has a buih in microcontroller to regulate the operation of a radio frequency (RF)

transceiver to transmit and receive CAN signals through Zigbee network. The micro controller may regulate a radio frequency transceiver to receive wireless signals transmitted through the ZigBee network and to transmit the received signals through CAN bus. The gate way unit may act as a full function device to provide an interface between the CAN and ZigBee network. The data received through CAN bus is transmitted through ZigBee network and vice versa. The gate way imit may act as a reduced function device to receive data from sensors or vehicle diagnostic tool or from different vehicle buses through CAN bus and to transmit the received data through RF transceiver to ZigBee network. The gate way unit may be programmed to act as a full function device or as a reduced function device. Software is loaded into the gateway unit to act as a full function device or reduced function device.
[0038] FIGURE.2 shows a block diagram of a gateway system used for transmitting the outputs of multiple sensors to multiple ECUs through single vehicle CAN bus, according to one embodiment of the present mvention. With respect to FIG.2, the gateway system has a coordinator or full function device, routers and reduced function device (RFD). The gateway system is employed to connect the multiple electronic control units to multiple sensors using a single vehicle CAN bus. The sensor out put data may be a tyre pressure data, wheel aligrmient data, the speed value, collision data etc. The RFD receives the input from the sensors and regulates RF transceiver to transmit the received sensor input to coordinator through ZigBee network. The coordinator regulates RF transceiver to receive the wireless data transmitted over the ZigBee network from the RFD. Multiple ECUs are connected to the single vehicle CAN bus which is in tum connected to the coordinator through a CAN bus. The built in microcontroller hi the coordinator regulates the RF transceiver

to pass the received sensor data to the respective control units through the CAN bus and the single vehicle CAN bus. Thus the data received from the RFD is sent to the respective electronic control units (ECU) through a single vehicle CAN bus by the coordinator over a CAN bus.
[0039] FIGURE.3 shows a block diagram of a gateway system used for transmitting the data from the muUiple buses to a single coordinator through multiple vehicle CAN buses and RFDs, according to one embodiment of the present invention. With respect to FIG.3, a gate way device is used to transmit the data from the multiple vehicles to a single coordinator through CAN and Zigbee protocols. Multiple ECUs are connected to respective vehicle CAN buses which are coimected to the multiple RFDs through respective CAN buses. The input data from the multiple vehicles are passed through the multiple vehicle CAN buses. The data passed through the multiple vehicle CAN buses are transmitted over the respective CAN buses to the multiple RFDs. The microcontroller in the RFD regulates the RF transceivers to receive the data transmitted through the CAN buses and to transmit the received data through ZigBee network to the coordmator. The microcontroller in the coordinator controls the RF transceiver to receive the data transmitted from the RFDs through ZigBee network. The received data are processed in the coordinator for the next stage based on the application. The processed result is displayed on a screen.
[0040] FIGURE.4 shows a block diagram of a gateway system used for ttansmittmg data in remote vehicle diagnostic system. With respect to FIG.4, a gateway system is used to transmit data to ECU in remote vehicle diagnostics system. The IlFD is connected to a vehicle diagnostic tool through a CAN bus. The built in

microcontroller in the RFD regulates the RF transceiver to receive the data sent from the vehicle diagnostic tool through the CAN bus. The input received from the vehicle diagnostic tool is sent to a coordinator through ZigBee communication network by the reduced function device. The microcontroller in the RFD controls the RF transceiver to transmit the received vehicle diagnostic data to the coordinator through the ZigBee network. Multiple ECUs are connected to a single vehicle bus which is in turn connected to the coordinator through CAN bus. The data received at the coordinator is sent to the respective ECU through CAN bus and vehicle CAN bus. The coordinator regulates the RF transceiver to receive the data transmitted through the ZigBee network from the RFD and to transmit the data to the ECU through CAN bus and vehicle CAN bus.
G) ADVANTAGES OF THE INVENTION
[0041] Thus the various embodiment of the present invention provide a gateway system and method to interface both the CAN and ZigBee networks in automotive applications to transmit the CAN packets through ZigBee Networks and to transmit the wireless packets over the CAN. The gateway system converts the wired CAN signals into wireless Zigbee signals and vice versa easily, efficiently and reliably. The system enables highly reliable and secure transmission of data using ZigBee and CAN communication protocols in automotive applications. The system consumes less power to transmit and receive data through ZigBee and CAN.

[0042] Although the invention is described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
[0043] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present invention described herein and all the

CLAIMS
What is claimed is:
1. A gateway communication system for Controller area Network and Zigbee
communication network, the system comprising:
A gate way unit;
Interface unit for CAN;
Interface unit for ZigBee network;
Transceiver units;
Wherein the gate way unit, the interface unit for CAN, the interface unit for
ZigBee network and transceiver units are mtegrally formed in a single printed
circuit board to provide interface between the CAN and the ZigBee networks.
2. The system according to claim 1, wherein the gate way unit is a coordinator.
3. The system accordmg to claim 1, wherein the gate way unit has built in microcontroller.
4. The system according to claim 1, wherem the microcontroller regulates the RF transceiver to transmit and receive data through CAN and ZigBee networks.
5. The system according to claim 1, wherein the gate way unit is loaded with application software.

6. The system according to claim 1, wherein the gate way unit acts as full
function device.
7. The system according to claim 1, wherem the gate way unit acts a reduced function device.
8. The system according to claim 1, wherein the gate way unit acts as the full function device or as the reduced function device based on the software loaded in the gateway unit.
9. The system according to claim 1, wherein the gate way unit converts the
wired CAN signal into wireless signals and vice versa.