Method for operating an ad-hoc network for the wireless data transmissions of synchronous and asynchronous messages

• US 20040063401A1
• Filed: 10/20/2003
• Published: 04/01/2004
• Est. Priority Date: 12/14/2000
• Status: Active Grant

• Current Assignee: 7 Layers AG
• Original Assignee: 7 Layers AG
• Inventors: Michael, Horn, Meckelburg, Hans-Jurgen
• Granted Patent: US 7,349,339 B2
• Time in Patent Office: Days
• US Class Current: 455/41.1
• CPC Class Codes: H04L 45/302 Route determination based on requested QoS
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 40/00 Communication routing or communication path finding
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

The invention relates to a method for operating an ad-hoc network for the wireless data transmission of synchronous and asynchronous messages. Said network consists of any number of randomly distributed network nodes, each having a receiver with an input controller, a switching station and a transmitter with an output controller. Transmission paths from a start node to a destination node, via intermediate nodes, are determined according to a routing method for the virtual connections that are to be transmitted. The nodes manage local address or control information, which is allocated to the virtual connections and transmitted to the preceding nodes of the transmission path. According to the invention, the transmitters and receivers of neighbouring nodes on a transmission path are synchronised using cyclically transmitted identifiers, whose intervals define a time frame. The nodes of the transmission path reserve time slots within the time frame for the transmission of data packets of a virtual connection that are to transmitted synchronously. A start signal is transmitted at the start of the synchronous transmission of a virtual connection, the data packets are then transmitted in the previously defined time slots and the synchronous transmission is concluded by a stop signal. Free time slots in the nodes are filled with data packets that can be transmitted asynchronously, said packets being read from an output buffer memory of the node.

Claims

1. Method for the operation of an ad hoc network for wireless transmission of synchronous and asynchronous messages,

whereby the network is composed of network nodes that are distributed in any desired manner, each of which has a receiving device having an input controller, a switching station, and a transmitting device having an output controller,

whereby transmission paths for logical connections to be transmitted from a starting node to a target node are established by way of intermediate nodes, according to a routing method, and

whereby the nodes administer local address and control data (LCI) that are assigned to the logical connections and are reported to the preceding node of the transmission path,

characterized in that

that the transmitting and receiving devices of adjacent nodes of a transmission path are synchronized, using cyclically transmitted identifiers, the distances between which define a time frame,

that the nodes of the transmission path reserve time slots within the time frame, for the transmission of data packets of a logical connection to be transmitted synchronously, whereby a start signal is sent at the beginning of a synchronous transmission of the logical connection, subsequently the data packets are transmitted in the previously determined time slots, and the synchronous transmission is concluded with a stop signal, and

that free time slots in the nodes are filled up with data packets transmitted asynchronously, which are read out from an output buffer of the node.

2. Method according to claim 1, characterized in that the data packets are transmitted according to a frequency multiplex method, in the form of symbol vectors, which consist of a fixed, predetermined number of symbols transmitted in parallel, and a header for identification of the symbol vector.

3. Method according to claim 1 or 2, characterized in that system-specific symbol vectors for synchronization of the transmitting and receiving device of adjacent nodes are transmitted within the established time frame.

4. Method according to claim 3, characterized in that a number of empty vectors is transmitted within the time frame, which are removed in a node, as needed, in order to eliminate synchronicity errors between the receiving and transmitting devices of adjacent nodes.

5. Method according to one of claims 1 to 4, characterized in that error recognition and correction takes place by way of a symbol vector and/or by way of a symbol stream that runs parallel.

6. Method according to one of claims 1 to 5, characterized in that after determination of a transmission path for a logical connection to be transmitted synchronously, a check is made as to whether the time slots required for the synchronous transmission are available on radio channels, and that all the nodes of the transmission path reserve the time slots and report the address data and the reserved time slot to the preceding nodes.

7. Method according to claim 6, characterized in that in the determination of the transmission path and the time slots for a connection to be transmitted synchronously, a time delay is proposed at a node if two independent logical connections between two nodes claim the same time slots, whereby all the time delays of the transmission path, from the starting node to the target node, are added, and the sum of the time delay for the synchronous transmission is not allowed to exceed a predetermined value.

8. Method according to one of claims 1 to 7, characterized in that the symbol vectors of a receiving channel that arrive at a node are switched to a transmitting channel that is different from the former, whereby the symbols that belong to a symbol vector are switched further in parallel and transmitted.