Gainspan Corporation

Sibasis Purohit

Pankaj Vyas

Vishal Batra

Indudharswamy G Hiremath

Venu Madhava Rao Kosuri

Sharath Jose

Daniel Jonathan Kurtz

A wireless device receives a packet from a sender node according to a routing protocol and determines a position information of the sender node. The wireless device calculates a distance to the sender node from the wireless device and discards the packet if the distance is outside of a range. Otherwise, the packet is processed according to the routing protocol. As a result, the approach may be suited to testing type environments where the wireless devices are proximately placed and yet one may wish to simulate real-world distances between the wireless devices.

Creation of a wireless mesh network among proximately located wireless devices

A wireless station hibernates in a duration. The wireless station switches off an oscillator in at least a part of the duration. The oscillator is used to drive a portion of the wireless station. In an embodiment, the portion of the wireless station corresponds to a time keeping circuit, the time keeping circuit being rendered inoperative in the duration due to switching off of the oscillator.

Wireless station relying on hibernation for power savings in a wireless local area network

A wireless device receives a sequence of packets in a first set of durations on a first wireless network according to a first wireless protocol. The border router forwards the received sequence of packets in a second set of durations on a second wireless network according to a second wireless protocol. None of the first set of durations overlaps with any of the second set of durations. The first set of durations and the second set of durations are realized according to time division multiplexing. The sequence of packets are received and forwarded by the wireless device using a shared transceiver. In an embodiment, the wireless device is a border router of a wireless mesh network, and the first wireless protocol and the second wireless protocol are respectively according IEEE 802.15.4 and IEEE 802.11.

Border router of a wireless mesh network extending connectivity of wireless stations to external networks

A wireless device operates in a first wireless network using a first wireless protocol to receive a set of provisioning parameters for joining a second wireless network that uses a second wireless protocol. The first wireless network may be based on a shared wireless broadcast medium. The wireless device then joins the second wireless network using the set of provisioning parameters. In an embodiment the first wireless protocol is according to IEEE 802.11 specifications, while the second wireless protocol is according to IEEE 802.1.5.4 specifications.

Provisioning a dual mode wireless device for operation in accordance with a layer-2 wireless protocol after being operational in accordance with another layer-2 wireless protocol

An aspect of the present disclosure enables each receiver node of a wireless network to synchronize active widows with those of the sender node. In an embodiment, a receiver node receives a packet from a sender node on a wireless network, with the packet including data indicating a position of the packet in an active window of the sender node. The receiver node determines the position at which the packet is received in an active window of the receiver node. The receiver node determines a difference between the two positions and adjusts a start position of the next active window (of the receiver node) based on the determined difference to synchronize the future active windows at the receiver node to respective active windows at the sender node.

Synchronizing active window boundaries used for data transmission between pairs of nodes of a wireless network

Router nodes of a wireless network deliver layer-3 multicast packets to subscribing end devices. In an embodiment, upon receiving a layer-3 multicast packet, a router determines a source that originated the layer-3 multicast packet. The router broadcasts at L2-level, the layer-3 multicast packet only if either one of a first condition and a second condition is satisfied. The first condition is satisfied only if (A) the source is not a descendant node of the router node according to the hierarchy, (B) the layer-3 multicast packet is received from a parent node, and (C) the layer-3 multicast address is subscribed to by a descendant of the router node. The second condition is satisfied only if (A) the source is a descendant of the router node, and (B) the layer-3 multicast packet is received from a child node according to the hierarchy, the source being reachable from the child node.

Multicast packet delivery in a wireless network operating in storing mode

A router node according to an aspect of the present disclosure maintains multicast information indicating child nodes registered for respective multicasts, while operating in a non-storing mode along with other router nodes of a wireless network for processing unicast packets. Upon receiving a layer-3 multicast packet, the router node examines the multicast information to identify a set of child nodes registered for the corresponding multicast. The router node thereafter unicasts, at L2-level, the layer-3 multicast packet to each child node of the set of child nodes. In an embodiment, the router node participates in a routing protocol (e.g., RPL) to form a hierarchy of nodes constituting the wireless network, with the hierarchy containing a root node and a set of end devices as leaf nodes.

Multicast packet delivery in a wireless network operating in non-storing mode

According to an aspect of the present disclosure, an access point sends timing information related to updating of a group key. A wireless station communicates with the access point according to the timing information to receive an updated group key. The updated group key is thereafter used for processing of multicast packets. Due to the use of the timing information, the wireless station can operate in a power-down mode, and yet receive at least the required group keys. In one embodiment, the timing information specifies a future time instance at which the update group may be available. In an alternative embodiment, a version number is associated with each value of the group key and the version number of the currently operative group key (in the access point) is broadcast to the wireless stations.

Updating of layer-2 group key in a wireless network

A wireless station in a WLAN generates a first set of data elements for sending to a final destination. The wireless station forms a first Internet Protocol (IP) packet with a header portion and a payload portion. The header portion specifies an IP address of a neighbor access point (AP) as the next hop destination. The payload portion of the IP packet includes an IP address of the final destination to indicate that the data elements are to be delivered to the final destination. The wireless station transmits the IP packet to the neighbor AP according to the IP address of the neighbor AP. Extended connectivity based on wireless paths between stations of a wireless local area network (WLAN) is thus provided.

Extended connectivity based on wireless paths between stations of a wireless local area network (WLAN)

A wireless network includes a border router, multiple router nodes and end devices. All nodes of the wireless network use a same group key for encryption and decryption of payloads of multicast layer-2 packets. A router node of the wireless network receives a group key from its parent node, and forwards the group key to its child nodes. The router node receives a layer-2 multicast packet with a payload specifying a multicast layer-3 address. The router node decrypts the payload using the group key. If at least one child node of the router node belongs to a group corresponding to the multicast layer-3 address, the router node forwards the encrypted payload as a layer-2 multicast packet to corresponding child nodes. Use of a same group key across all nodes of the wireless network reduces storage space in a node for storing group keys, and also simplifies group key handling.

Security for group addressed data packets in wireless networks

A first wireless device of a wireless local network is operated in an un-associated data transfer mode at a layer-2 level. In the un-associated data transfer mode, communication between the first wireless device and a second wireless device in the wireless local network is allowed to take place without prior authentication and association between the two wireless devices. The first wireless device participates in formulation of routing information in routing nodes of a wireless mesh network while operating in the un-associated data transfer mode. If configured as an end device, the first wireless device thereafter exchanges data packets with another wireless device in the mesh. If configured as a router, the first wireless device routes packets to corresponding wireless devices in the mesh. Operation in the un-associated data transfer mode may result in reduction in power consumption of nodes in the mesh, as well as increased data throughput.

Layer-3 mesh connectivity of wireless local networks

A router in an embodiment associates a corresponding digital code of a set of digital codes to a respective portion of a network address of set of network addresses used in routing information. The routing information is stored in a memory with each digital code substituted for the respective portion of the network address. Memory reduction is obtained as a result. In an embodiment implemented in the context of IPv6 having a prefix and a host identifier for each network address, the portion of a network address corresponds to the prefix. The routing information is stored in the form of a prefix table and topology information. The prefix table stores a mapping of each digital code to a corresponding prefix. The topology information indicates a manner in which each host system and router are connected to each other. Packets are forwarded by examining such routing information.

Maintaining routing information in memory constrained routers

An aspect of the present invention populates data structures of a software application with input data provided according to XML. In one embodiment, the input data and a schema is received, with the schema containing another set of data structures according to the programming language in which the software application is written. The input data is parsed according to the schema to identify elements and corresponding values. The identified values are then stored in the fields of the data structures of the application. According to another aspect, the schema received with the input data specifies a mapping of each of the elements in the input data to corresponding fields of data structures of a software application. Accordingly, the specified fields of the data structures are set to the values associated with the corresponding mapped elements in the input data.

Populating data structures of software applications with input data provided according to extensible markup language (XML)

An end device in a network is designed to operate consistent with multiple versions of the internet protocol. The end device determines which version of the internet protocol, according to which the network is operative, by monitoring a set of packets on the network. Based on the determination of the version of internet protocol, the end device loads in an internal volatile memory only those instructions and data required for operation according to the determined version. Instructions and data required for operation according to other version(s) are not loaded into the volatile memory. Size requirements of the volatile memory are thereby reduced.

Reducing the size of volatile memory in an end device designed to operate with multiple versions of internet protocol

A wireless station (A) is operated in a power-save mode, in which the station is alternately in power-ON and power-OFF states to reduce power consumption. Wireless station (A) computes at least some future time instances at which another wireless station (B) is expected to start transmitting control messages. Wireless station (A) is ensured to be in the power-ON state in corresponding time intervals encompassing durations of at least some of such future transmissions of control messages by wireless station (B), and is thereby enabled to receive the control messages. In an embodiment, the control messages correspond to group key message updates in which values of a decryption key are transmitted, wireless station (A) being a wireless client, wireless station (B) being an access point, with wireless stations (A) and (B) operating in a wireless network consistent with IEEE 802.11 specifications, and communication between wireless stations (A) and (B) being encrypted.

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Bengaluru, India

Sibasis Purohit