Title of Invention

METHOD AND DEVICE FOR ASSIGNING INTERNET PROTOCOL (IP) ADDRESS IN A WIRELESS PERSONAL AREA NETWORK (WPAN) ENVIRONMENT

Abstract

This invention relates to the IP address assignment of devices that participate in a WPAN network and to steps for utilizing IP based WPAN application in a Point to point to environment. The invention explains a system and method for IP address assignment to a device in a WPAN environment wherein a device address allocation by MAC is used and the MAC provides the notification of device address change to the appropriate layer where the IP address assignment is being handled.

Full Text

FIELD OF THE INVENTION The present invention relates to the field of wireless networks. Further, this invention relates to Network Layer for wireless personal area networks (WPAN) that are based on wireless mobile ad-hoc networks. This invention, further, relates to the Network layer (IP layer) functionality of WPAN. Specifically, this invention relates to the IP address assignment of devices that participate in a WPAN network and to steps for utilizing IP based WPAN application in a Point to point to environment. The invention encompasses a system and method for assignment of unique IP addresses for each node that participate in a WPAN environment. More particularly, the present invention relates to system and method for IP address assignment in a WPAN environment DESCRIPTION OF RELATED ART The wireless personal area networks are defined to operate in the personal operating space, i.e. in a range of approximately 10 meters. The WiMedia Alliance (http://www.wimedia.org) is involved in defining standards for such wireless personal area networks. The Ultra Wide Band (UWB) technology can provide data rates exceeding several hundreds of Mbps in this personal operating space. In wireless personal area networks, the medium is shared between all the devices for communication with each other. This necessitates a medium access control mechanism for the devices to manage medium access, broadly including how it may join the network, can transfer data at the required rate to another device, how the medium is best used, how to detect and resolve beacon collisions etc. Medium access control for wireless personal area networks is designed in distributed manner. The medium access operations are distributed evenly across all devices in the network and all the devices share the load of managing medium access operations for each other. Figure 1 show the wireless personal area network, which is based on distributed approach and which does not have any centralized coordinator. It involves a decentralized WPAN, in which devices are light coordinator and there is no dedicated coordinator present. All devices cooperate and share information with each other to perform the medium access control tasks such as allowing a new device to join, allocation of channel time to a device to transmit data to another device, synchronization mechanisms etc. This is a Distributed WPAN system which is formed in an ad-hoc fashion. Each device periodically broadcasts the information about its neighbors and allocated channel time to its neighbors. The Distributed medium access control approach relies on a timing concept called the Superframe. Superframe has a fixed length in time and is divided into a number of time windows which are called time slots. Some of the time slots are used by the devices to send their beacons and the other are used by the devices to send the data. The slots in which beacon is sent are called beacon slots and the slots in which data is sent are called data slots. The length of a beacon period may be less than the length of a data period. The beacon slots may be distributed across the slots in the superframe or may appear together at the start of the superframe. In addition, the number of beacon slots may be fixed or variable leading to different configurations of Distributed Medium Access Control mechanisms. Figure 2 illustrates the superframe structure, specified by the WiMedia MAC. It consists of several Medium Access Slots (As an example, the number is shown as 256). Some Medium Access Slots (MAS) constitute beacon period (comprising of beacon slots corresponding to multiple devices) and remaining MASs constitute data period (comprising of data slots that may be used by different devices in the network to transmit data to other devices in the network), employs a superframe duration of 65,536 micro-second with 256 MASs, and each MAS is of 256 microsecond duration. Information about superframe is being broadcasted by each device in its broadcasted beacons, so neighbors of that device can use that information for further processing. The start time of the superframe is determined by the beginning of the beacon period and defined as the beacon period start time (BPST). Devices that belong to the same beacon period shall utilize the same BPST for the superframe. However, some of the devices may define a different time as their BPST. In such case, 2 or more beacon groups may coexist for the device. MASs are numbered relative to this starting time. The devices shall transform the numbering of MASs of other beaconing periods into the time reference of their main Deaconing period. A device can be part of several beaconing periods but has to select one beaconing period as its main beaconing period. MASs can be reserved through Distributed Reservation Protocol (DRP). The reservation can be of different reservation type like Hard, Soft, PCA (Prioritized Contention Access) or Private. All reservation type uses different access method to access the channel. Private reservation type does not define any access method; it is up to the implementation to use an access method in private reservation. Each device which is target of the reservation or owner of the reservation sends a DRP IE in their beacon. In a network formed by WPAN devices, the MAC layer assigns unique device addresses to each device that are part of its cluster. Device uses 16 bit device address (DevAddr) as an addressing entity. Two type of addressing is defined by WiMedia MAC. Address called generated address is generated by the device randomly and its range is from 0x0100 to OxFEFF. If the same address is found used in neighborhood by some other device then the device will generate new address and, this procedure is called address conflict resolution. Another type of address is called Private address. Private address is not generated by the device, but assigned by some other means. The range of private addresses is from 0x0000 t0 OxOOFF. In addition, range OxffOO - Oxfffe is reserved for Multicast addresses and Oxffff is reserved for broadcast address. According to the current WiMedia system architecture, WiMedia enables different application protocols like IP, USB, IEEE 1394, etc. to utilize the WiMedia common radio platform through a Protocol Adaptation Layer (PAL). The IP specific PAL is WiNET and IP layer sitting above WiMedia MAC will utilize the service of WiNET to make use of the WiMedia common radio platform. IP based applications work with an IP address and IP addresses are a unique entity bound to a device. IP addresses are 32 bits in length and are made of 2 parts - Network address part and Host address. The first set of octets (from octet 1 to 3) defines the network part of the IP address and the next set of octets (from octet 2 to 4) defines the Host part of the IP address. If the first 3 octets defines the Network part of the IP address and the rest 1 octet defines the host address, then that type of IP address are called Class C. If 2 octets define the Network part of the IP address and the rest 2 octets define the host address, then those types of IP addresses are called class B IP address. If only 1 octet defines the Network part of the IP address and the rest 3 octets addressing the host address, then those IP address are called Class A IP address. In an IP based Network, an IP address can be assigned either statically or dynamically. In the case of dynamic IP address allocation, devices utilize a protocol known as the Dynamic Host Configuration Protocol (DHCP) to request dynamic IP address from a central entity called the DHCP Server. DHCP is defined in RFC 2131. In scenarios where such a centralized infrastructure to distribute IP addresses may be infeasible, another method known as ZeroConf or Zero Configuration is used for automatically creating usable IP address for a device without the use of special servers. Zero Configuration is defined in RFC 3927. Using DHCP or ZeroConf mechanisms to derive an IP address dynamically is appropriate for a wired environment, but, when the environment is mobile and unreliable wireless PAN such as WiMedia, a more reliable mechanism is appropriate. A WiMedia kind of WPAN environment operating in a Personal Operating Space is ad hoc in nature and is designed to be adapted to any kind of network environments like home, office etc. Hence it is unreasonable to expect a dedicated server to provide IP address as needed while using DHCP mechanism. In addition, the ZeroConf mechanisms are not very suited to the WPAN domain due to its mobility and the inherent cost of broadcasting protocol packets throughout the network, as needed by the ZeroConf mechanism. SUMMARY OF THE INVENTION The primary objective of this invention is to provide a simple method for assigning IP addresses for WPAN nodes. Another objective of this invention is to provide a simple mechanism that will allow the new IP address assigned WPAN node to work as a subnet to the node that has assigned the IP address. Another objective of the invention is to provide a mechanism where all the nodes in WiMedia WPAN can get an IP address which enables the device to be reachable from the outside of the WPAN cluster. The present invention comprises of system and method which would solve the problems associated with related art, in the following manner: 1. A new method for deriving IP addresses for a WPAN environment which is tightly coupled with beaconed non-centralized MAC architecture like the one in WiMedia MAC. 2. Methodology to mutually exclude to avoid duplication of already assigned IP address for a WiMedia Node. 3. Methodology for enabling how a device can be accessed from outside the WPAN operating space through its IP address. 4. Method for advertisement of IP address in the beacon. 5. Method to allow a special device called the gateway to control the proposed method by advertising subnet address in its beacon. Accordingly, the invention provides a system and method for easy assignment of IP addresses specifically tailored for a WPAN wireless environment. Accordingly, this invention encompasses a method for IP address assignment to a device in a WPAN environment wherein a device address allocation by MAC is used and the MAC provides the notification of device address change to the appropriate layer where the IP address assignment is being handled. The device address allocation by MAC involves the WiMedia MAC layer scanning the wireless channel to determine the devices in the neighborhood of the device when a device starts up. WiMedia MAC assigns the device address to a device using a generation algorithm which uses the device's EUI 48 address if present. The MAC layer checks the generated address for conflicts with the addresses of the neighbors and in case of device address conflict, MAC regenerates the device address to resolve the conflict. If the device complies with the WiMedia MAC, the said device have a unique ID assigned and in presence of the uniquelD, the MAC generates a two byte address in the generated device address range. Devices which do not have this unique ID choose a device address randomly from the range of private device addresses. IP Address assigning involves generating unique IP addresses having four bytes in length for the device using the unique MAC device address assigned to the device by the MAC where the network ID part of the IP address, generated is fixed to two bytes and the remaining two bytes are fixed for the host ID part. The WPAN is further sub-netted by using gateway device which broadcasts the subnet ID information to its cluster in its beacon. To generate the IP address, the device MAC layer generates a unique MAC address for the device where the generated MAC address is used as the last two bytes of its IP address. If the device has a gateway device in its cluster which broadcasts the subnet ID in its beacon, the device uses the broadcasted subnet ID as the first two bytes of its IP address. If the device does not have any gateway device or the subnet ID could not be received, the device uses the default subnet ID as the first two bytes of its IP address. If the MAC address of the device changes due to address conflicts, the device generates a new IP address for its use where the device continue to recognize its old IP address for a duration of time to continue with the communication in progress during the event of IP address change. The device follow the IP protocol to advertise its new IP address. When the device locates more than one gateway devices in its cluster, each broadcasting its own subnet ID, and the device generates more than one IP address, each valid for the appropriate subnet as identified by the gateway device where appropriate IP address is used for communicating with appropriate gateway or for devices in different subnets. Gateway devices incorporate WiMedia MAC and Physical layer and connect the PAN to another network having a different protocol stack. The gateway device routes all traffic from the PAN to the other network and vice versa where all PAN devices use the Gateway device as an IP routing element to communicate with devices not present in the same subnet or network. Gateway devices broadcast a subnet IE in their beacon where the IE contains a two byte subnet ID which is used by the PAN devices to generate their unique IP addresses. Accordingly, this invention further provides a system for IP address assignment to a device in a WPAN environment operated by the above said method wherein a device address allocation by MAC is used and the MAC provides the notification of device address change to the appropriate layer where the IP address assignment is being handled. These and other objects, features and advantages of the present invention will become more apparent from the ensuing detailed description of the invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Figure 1 illustrates the WPAN as a decentralized and distributed ad-hoc network system and range of all devices. Figure 2 illustrate the superframe structure in current art, which includes MASs and a dynamic beacon period (i.e. a BP with dynamic length). DETAILED DESCRIPTION OF THE INVENTION The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However in certain instances, well-known or conventional details are not described in order not to unnecessarily obscure the present invention in detail. The present invention relates to a system that allows a method of assigning IP address in the decentralized Wireless Personal Area Networks based on mobile ad-hoc networks. Accordingly, the invention provides a system and method for communicating the IP address between the devices those are part of the Wireless Network. The invention provides a mechanism where the IP assigned WPAN node can be contacted from outside the WPAN environment. The subsequent subsections describe the invented objects to effect the invention and the operation of the invention: 1. Device Address Allocation by MAC: When a device starts up, the WiMedia MAC layer has provision to scan the wireless channel to determine the devices in the neighborhood of the device. All devices send periodic beacons, once every super frame, which contains its two byte device address. WiMedia MAC assigns the device address to a device using a generation algorithm which uses the device's EUI 48 address (if present). Further, the MAC layer checks the generated address for conflicts with the addresses of the neighbors. In case of device address conflict, MAC has provisions to regenerate the device address to resolve the conflict. Devices which fully comply with the WiMedia MAC usually have a 48 bit unique ID assigned to them by a regulatory body. In case such an ID is present, the MAC uses this ID to generate a two byte address in the generated device address range. This ensures higher probability of generating unique device addresses for the devices and reduces the probability of device ID conflicts. Devices which do not have this unique ID are required to choose a device address randomly from the range of private device addresses given that such a choice has not already been picked up by any device in the cluster. The proposed method of IP address assignment uses the device address provisioned for the device by the MAC. Whenever such an address is generated for the device, at the very beginning of device operation or as a result of device address conflict resolution, the mechanism of the proposal must be used to generate a new IP address for the device. The MAC should provide the notification of device address change to the appropriate layer where the IP address assignment is being handled. It should be noted that the above description should not be construed to limit the scope of the invention. It is only there to show clearly the application of the proposed method in the domain of WiMedia PAN. Similar application can easily be made, due to the nature of the system and method proposed, in other PAN environments by adopting the proposed method of the invention to the MAC address allocation method of the PAN. 2. IP Address Allocation IP Addresses are four bytes in length and are made up of a network ID and a host ID. The proposed method generates unique IP addresses for the device using the unique MAC device address assigned to the device by the MAC. The network ID part of the IP address, generated by the proposal is fixed to two bytes. The remaining two bytes are fixed for the host ID part. In essence, IP addresses generated by the proposal allow for a network of 65536 devices in the same subnet. The PAN can be further sub-netted by using a special type of device called the gateway device which broadcasts the subnet ID information to its cluster in its beacon. To generate the IP address, the device takes the following steps: Device MAC layer generates a unique MAC device ID address for the device - The device uses the generated device ID address as the last two bytes of its IP address - In case the device has a gateway device in its cluster which broadcasts the subnet id in its beacon, the device uses the broadcasted subnet id as the first two bytes of its IP address. In case no such gateway device is present or the subnet ID could not be received, the device uses the default subnet ID of 169.254 as the first two bytes of its IP address. - Whenever the MAC device address of the device changes due to address conflicts, the device repeats the same procedure to generate a new IP address for its use. The device should continue to recognize its old IP address for some duration of time to continue any communications in progress during the event of IP address change. - The device should follow the normal provision of the IP protocol to advertise its new IP address. - In scenarios where the device locates more than one gateway devices in its cluster, each broadcasting its own subnet id, the device should generate more than one IP address, each valid for the appropriate subnet as identified by the gateway device. Appropriate IP address must be used for communicating with appropriate gateway or for devices in different subnets. 3. Gateway Device Gateways are devices commonly used in IP based network environment, in the context of this invention, the gateway devices are expected to incorporate WiMedia MAC and Physical layer. Gateway as applied here is a device which connects the PAN to another network having a different protocol stack. In the proposed method, gateway devices help in the following ways: - Gateway device routes all traffic from the PAN to the other network and vice versa. - All PAN devices use the Gateway device as an IP routing element to communicate with devices not present in the same subnet or network. - Gateway devices broadcast a Subnet IE in their beacon. This IE contains a two byte subnet ID which is used by the PAN devices to generate their unique IP addresses. Different gateways may use different subnet IDs to segregate the PAN devices into virtual IP networks. - Gateway device may use some fixed infrastructure to provision a subnet ID for the use in the PAN or use the fixed private link layer auto configuration subnet of 169.254. - Gateway devices should act as a proxy for all traffic from/to PAN devices which private IP addresses not visible beyond the subnet. In case the gateway has provisioned public IP addresses for the nodes, the gateway can act as a transparent router. - Gateway devices assign themselves an IP address generated using the proposed method as explained. In addition, the gateway may have additional static or dynamic IP addresses due to their connection to multiple networks. - Gateway node should maintain a list of all the devices with their IP address as discovered on the PAN side. Gateway nodes should determine from the incoming traffic the appropriate IP address to use for the PAN device and should route the traffic to that device. In case the PAN devices use private IP addresses, the gateway may act as a home agent server to register the IP addresses of the PAN devices making them accessible to the outside world. It will also be obvious to those skilled in the art that other control methods and apparatuses can be derived from the combinations of the various methods and apparatuses of the present invention as taught by the description and the accompanying drawings and these shall also be considered within the scope of the present invention. Further, description of such combinations and variations is therefore omitted above. It should also be noted that the host for storing the applications include but not limited to a microchip, microprocessor, handheld communication device, computer, rendering device or a multi function device. Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom. GLOSSARY OF TERMS AND DEFINITONS THEREOF ACK: Acknowledge BP: Beacon Period BPST: Beacon Period Start Time CTA: Channel Time Allocation DevAddr: Device Address DN: Device Notification DrCTA: Device Receive Channel Time Allocation DRP: Distributed Reservation Protocol DtCTA: Device Transmit Channel Time Allocation IE: Information Element IP: Internet Protocol MAC: Medium Access Control MAS: Medium Access Slot PAN: Personal Area Network PCA: Prioritized Contention Access PHY: Physical Layer USB: Universal Serial Bus UWB: Ultra Wide Band WPAN: Wireless Personal Area Network WUSB: Wireless Universal Serial Bus WE CLAIM 1. A method for IP address assignment to a device in a WPAN environment wherein a device address allocation by MAC is used and the MAC provides the notification of device address change to the appropriate layer where the IP address assignment is being handled. 2. A method as claimed in claim 1 wherein IP Address assigning involves generating unique IP addresses having four bytes in length for the device using the unique MAC device address assigned to the device by the MAC where the network ID part of the IP address, generated is fixed to two bytes and the remaining two bytes are fixed for the host ID part. 3. A method as claimed in claim 2 wherein the WPAN is further sub-netted by using gateway device which broadcasts the subnet ID information to its cluster in its beacon. 4. A method as claimed in claim 3 wherein to generate the IP address, the device MAC layer generates a unique MAC address for the device where the generated MAC address is used as the last two bytes of its IP address. 5. A method as claimed in claim 4 wherein if the device has a gateway device in its cluster which broadcasts the subnet ID in its beacon, the device uses the broadcasted subnet ID as the first two bytes of its IP address. 6. A method as claimed in claim 5 wherein if the device does not have any gateway device or the subnet ID could not be received, the device uses the default subnet ID as the first two bytes of its IP address. 7. A method as claimed in claim 6 wherein if the MAC address of the device changes due to address conflicts, the device generates a new IP address for its use where the device continue to recognize its old IP address for a duration of time to continue with the communication in progress during the event of IP address change. 8. A method as claimed in claim 7 wherein the device follow the IP protocol to advertise its new IP address. 9. A method as claimed in claim 8 wherein when the device locates more than one gateway devices in its cluster, each broadcasting its own subnet ID, and the device generates more than one IP address, each valid for the appropriate subnet as identified by the gateway device where appropriate IP address is used for communicating with appropriate gateway or for devices in different subnets. 10. A method as claimed in claim 5 wherein gateway devices incorporates WiMedia MAC and Physical layer and connects the PAN to another network having a different protocol stack. 11. A method as claimed in claim 10 wherein the gateway device routes £11 traffic from the PAN to the other network and vice versa where all PAN devices use the Gateway device as an IP routing element to communicate with devices not present in the same subnet or network. 12. A method as claimed in claim 11 wherein gateway devices broadcast a subnet IE in their beacon where the IE contains a two byte subnet ID which is used by the PAN devices to generate their unique IP addresses. 13. A system for IP address assignment to a device in a WPAN environment operated by the above said method wherein a device address allocation by MAC is used and the MAC provides the notification of device address change to the appropriate layer where the IP address assignment is being handled. 14.A method for IP address assignment to a device in a WPAN environment substantially described particularly with reference to the accompanying drawings. 15.A system for IP address assignment to a device in a WPAN environment substantially described particularly with reference to the accompanying drawings.

Documents:

1871-CHE-2005 CORRESPONDENCE OTHERS 06-02-2013.pdf

1871-CHE-2005 AMENDED CLAIMS 01-08-2012.pdf

1871-CHE-2005 AMENDED CLAIMS 31-05-2012.pdf

1871-CHE-2005 AMENDED PAGES OF SPECIFICATION 01-08-2012.pdf

1871-CHE-2005 AMENDED PAGES OF SPECIFICATION 31-05-2012.pdf

1871-CHE-2005 CORRESPONDENCE OTHERS 01-08-2012.pdf

1871-CHE-2005 EXAMINATION REPORT REPLY RECEIVED 31-05-2012.pdf

1871-CHE-2005 FORM-1 31-05-2012.pdf

1871-CHE-2005 FORM-13 01-08-2012.pdf

1871-CHE-2005 FORM-13 19-06-2006.pdf

1871-CHE-2005 OTHER PATENT DOCUMENT 06-02-2013.pdf

1871-CHE-2005 POWER OF ATTORNEY 01-08-2012.pdf

1871-CHE-2005 POWER OF ATTORNEY 06-02-2013.pdf

1871-CHE-2005 POWER OF ATTORNEY 31-05-2012.pdf

1871-che-2005-abstract.pdf

1871-che-2005-claims.pdf

1871-che-2005-correspondnece-others.pdf

1871-che-2005-description(complete).pdf

1871-che-2005-description(provisional).pdf

1871-che-2005-drawings.pdf

1871-che-2005-foem13.pdf

1871-che-2005-form 1.pdf

1871-che-2005-form 26.pdf

1871-che-2005-form 5.pdf