Abstract: A method for operating a wireless mesh data network with multiple nodes, wherein data frames are transmitted from a source node via one or more intermediate nodes to a destination node, wherein the source node, the one or more intermediate nodes, and the destination node constitute network nodes of the data network, wherein during transmission of a data frame, at least some of the network nodes which receive the data frame, using a precursor list for the destination nodes which is assigned to the destination nodes of the data frame, check whether the network node sending the data frame is in the precursor list, and wherein in the case of a positive result, the data frame is transmitted to a further network node, and in the case of a negative result, the data frame is thrown out or processed by an error recovery routine.

Abstract: A device for optically focusing a projection image projected by a projector includes a detector for controlled creation of at least one observation shot of the projection image over a time period, a processing unit for defining at least one image section within the projection image generated by the projector, where the image section is modulated over the time period with respect to the optical power and/or the optical spectrum thereof, and the at least one image section of the projection image is essentially synchronous compared with the corresponding respective image section of the observation shot, where the processing unit also calculates a variable derived from the comparison of the respective image sections and a control signal derived from the derived variable, and outputs the control signal to a focusing device of the projector.

Abstract: The invention relates to a method and a device for which, for determining a routing-metric for a mesh-network, in particular according to standard IEEE 802.11s, routing messages sent in wireless mesh networks or mobile ad-hoc-networks, on various paths of source nodes, via the mesh nodes of the mesh networks to the target nodes, are evaluated in order to determine the best path for transferring data packets from source nodes to target nodes. Said nodes are battery-operated and mesh nodes are only used in the energy-saving mode as intermediate nodes of a path when this can not be prevented due to necessary connectivity in the mesh network or due to predetermined guidelines. Also, in each routing message sent from source nodes to target nodes via various paths, a plurality of bits, preferably two bits, are used for the number of mesh nodes operating in the path in the energy-saving mode or are battery-operated when the remaining bits of the routing-message are used for the path metric.

Abstract: A method for providing visible notification by a device in a visible-light-communication system based on Institute of Electrical and Electronic Engineers (IEEE) standard 802.15.7, wherein higher levels are allowed to invoke through one standardized interface a medium-access-control sub-layer to provide color-function support and enables invocation of a transmission of color, visibility, and dimming frames by a higher layer, which creates a unified interface between the MAC sub-layer and the higher layers, while providing a primitive for requesting, by the at least one upper layer to the at least one interface of the medium-access-control entity layer, a transmission of at least one visibility frame.

Abstract: A congestion notification element for indicating a congestion status of a mesh node may include at least one field specifying a mesh destination for which an intra-mesh congestion control is to be applied. This may allow for forwarding data frames on paths that share some links but not the bottleneck link with a path that is congestion controlled, which has not been possible with currently specified congestion notification techniques.

Abstract: A method is disclosed for advertising channel reservations by an advertisement in a wireless mesh network, the advertisement being adapted for at least partially advertising channel reservations known by a transmitting node. The method includes: mapping at least one channel reservation to an advertisement element identifier, the advertisement element identifier identifying an advertisement element; considering said advertisement element to contain a set of channel reservations assigned to said advertisement identification number; and advertising said reservation by transmitting said advertisement element characterized by said advertisement element identifier.

Abstract: The invention relates to a method for operating a mesh network, especially according to IEEE standard 802.11s, wherein the mesh network comprises a plurality of network nodes, which have outer edge nodes and inner network nodes. A first edge node forms a connection point for external first stations disjunctive to the network, and a second edge node forms a connection point for external second stations disjunctive to the network, wherein data packets are to be exchanged between the first and second stations. During a switch of an external station from one edge node to another edge node, especially from a coverage area of the first edge node to a coverage area of the second network node, the respective association information of the network nodes is updated by means of an association message while inserting a validity duration for the association of the external stations connected to the edge nodes. The invention also relates to a device for carrying out the method for operating a mesh network.

Abstract: A method for making safety mechanisms available in wireless mesh networks which have a plurality of nodes that are interconnected by multi-hop communication in a wireless network meshed by mesh routing in the MAC layer, every node being active as a router to forward the data traffic of the other nodes. At least two differentiated levels of confidence are defined by a type of protection (ToP) the value of which represents a specific level of confidence for the nodes and data packets, the data packets being labeled with a ToP value in the mesh header, and at least one ToP value being allocated to the participating nodes, the nodes forwarding the data packet in the mesh network using the ToP values of the node and of the data packet if this ToP value combination is admissible in the node.

Abstract: A method is provided for configuring temporal parameters of an access scheme synchronized with other access schemes in a wireless mesh network based IEEE 802.11s specifications. In conventional access schemes an unsuitable choice of parameters at different neighboring mesh stations, especially an unsuitable choice of different DTIM intervals at the different neighboring mesh stations, will lead to overlapping reservations in some intervals. Thus, a method for setting a DTIM interval of a mesh station is provided, whereby a joining mesh station determines a DTIM interval of at least one mesh station of the wireless mesh network, and whereby the joining mesh station sets its own DTIM interval to the same DTIM interval, to a multiple of the DTIM interval, or to a fraction of the DTIM interval of at least one mesh station of the wireless mesh network, wherein the factor and the divisor are positive integers.

Abstract: According to the known IEEE 802.11s Draft Standard for WLAN Mesh Networking, version D5.0, the size of an information element is restricted to a length of 255 octets. Due to the definition of an MCCAOP advertisements element as a general information element this restriction is a major drawback leading to a maximum of 62 MCCA reservations to be advertised by an MCCAOP advertisements element. Although this number of reservations might be sufficient in the majority of situations, it is easily imaginable that there are situations which could require an advertisement exceeding this limit of 62 MCCA reservations. According to the disclosure, an MCCAOP advertisement—which is a set of MCCAOP reservations that needs to be advertised—is split over multiple MCCAOP advertisements elements. This may advantageously allow advertising more than 62 MCCAOP reservations to neighboring mesh nodes in a wireless mesh network which is configured to use MCCA.

Abstract: A method for optically transmitting data between a transmitter and a receiver is provided, wherein a color coding method based on a plurality of elementary colors is provided for encoding and transmitting the data, wherein each elementary color is transmitted by a transmitter-side optical radiation source and is received on the receiver side by an optical radiation receiver. The method includes transmitting a training request message comprising calibration information formed on the transmitter side; forming a channel properties matrix by the receiver from the calibration information and storing the channel properties matrix in the receiver; calculating at least one compensation information on the basis of a reference channel properties matrix stored in the receiver and the reference channel properties matrix; and transmitting the compensation information from the receiver to the transmitter.

Abstract: Network access node for a terminal integrated wirelessly into the network, including: a) a memory device having at least one first key and address codes for second access nodes for the terminal, b) at least one data communications device for exchanging data with the second access nodes, c) connected with the memory device and the data communications device, a processor with functions for: d) deriving second keys, among them a second key for securing the connection between the terminal and the second access node, from the first key, e) secured association of the terminal by using a key derived from the first key, f) in response to the execution of function d), transmission of the second key for securing the connection between the terminal and the second access node through the data communications device via secured connections and through addressing using the address codes, wherein the second keys also include the key used for step e).

Abstract: Embodiments relate to a key distributer node (AS) for a network, which comprises: a) a memory device (1) with at least one first key, b) at least one data communication device (2) that can exchange data with first and second access nodes (MAP1, MAP2) for a terminal (STA) integrated wirelessly into the network, c) at least one processor (3) connected to the memory device (1) and the data communication device (2), wherein functions are provided for the processor(s) that allow authentication of the terminal (STA) at the second access node (MAP2) in response to a key request received by the second access node (MAP2), d) a derivation of a second key from the first key, and e) triggered transmission of the second key through the data communication device to the second access node (MAP2). Connections to the network's first and second access nodes (MAP1, MAP2) with security relationships are provided for the key distributor node (AS) when using the first key.

Abstract: A method for transmitting a beacon for a star network in manufacturing automation, for use in a communications protocol, such as IEEE Standard 802.15.4e, for manufacturing automation, using at least one gateway and at least one sensor node, wherein the beacon comprises a field including information about a number of base time slots in a superframe.

Abstract: A method for establishing a bidirectional communication path in a wireless network, where the network includes nodes comprising a sink node and a plurality of subscriber nodes, and where the communication path for the bidirectional transmission of data packets is to be established between the sink node and at least one queried node of the subscriber nodes. An uplink path from a particular subscriber node to the sink node is determined by periodically exchanging path messages between adjacent nodes of the network, where a particular path message signals the respectively shortest distance to the sink node, i.e., as a metric. A downlink path from the sink node to the at least one queried node is determined by inserting an address list into at least one of the path messages sent by the sink node, which list comprises the address of a respectively queried node.

Abstract: Embodiments of the invention relates to a method for operating a mesh-type network, particularly as defined in an IEEE 802.11s standard, formed by a plurality of network nodes, said network operating at least a first network node that functions as access point for stations which are dissociated from the network and a second network node that functions as connector point for stations that are dissociated from the network. When switching a dissociated station from a radio service area of the first network node to the radio service area of the second network node in said mesh network, an updating of allocation information of nodes based on a route error message which is defined according to a routing protocol valid for the mesh network is carried out.

Abstract: An association update message for mesh networks according to the IEEE 802.11s standard provides the ability to include a plurality of associations in an association update message and thus ensure simultaneous updating of a plurality of associations of representative nodes with respect to the proxy nodes (proxy mesh stations) thereof. A threatened inconsistency in an association update in conventional systems, which provides for only one transmission of an association update message per association update, is thereby eliminated. The proxy information field has an identification field with a plurality of identification fields. The identification fields advantageously allow variable structuring of the proxy information fields, that is, dependent on the information transmitted, which also provides the ability to prevent redundant information in the proxy information fields.

Abstract: The invention relates to a method for making safety mechanisms available in wireless mesh networks which have a plurality of nodes that are interconnected by multi-hop communication in a wireless network meshed by mesh routing in the MAC layer, every node being active as a router to forward the data traffic of the other nodes. At least two differentiated levels of confidence are defined by a type of protection (ToP) the value of which represents a specific level of confidence for the nodes and data packets, the data packets being labeled with a ToP value in the mesh header, and at least one ToP value being allocated to the participating nodes, the nodes forwarding the data packet in the mesh network using the ToP values of the node and of the data packet if this ToP value combination is admissible in the node.

Abstract: A beacon for a star network comprising a gateway and at least one sensor node, where the beacon includes fields containing information on the length of a base time-slot and information on the number of used base time-slots per management time-slot, where the management time-slots are used at least to transmit configurations for the star network. In addition, the sensor node in the star network includes a data structure for saving a star network configuration, and the data structure includes a configuration gateway ID and a configuration sequence number as attributes.

Abstract: A method for data transmission in a local area network, wherein data is transmitted on a medium access control layer within successive time frames between a plurality of first nodes comprising client nodes and a second node within reach of the first nodes, and a coordinator node for the first nodes where a time frame comprises a plurality of time slots. Each time slot is assigned to a first node that is a slot owner node being exclusively allowed to start transmitting data at a time within a first interval at the beginning of the time slot. At least one first nodes of the plurality of first nodes is allowed to use the time slot based on a contention based access to transmit the data in a second interval succeeding the first interval where the slot owner node has not started transmitting data at a time within the first interval.