Siemens Aktiengesellschaft

Matthias Kutschenreuter

Christian Schwingenschlögl

Michael Bahr

Andreas Ziller

Claus Gruber

A method for transmitting data in a wireless radio network having a multiplicity of base stations for wirelessly sending and receiving data, wherein the base stations are wirelessly networked such that each base station can communicate wirelessly with one or more adjacent base stations. Broadcast messages are transmitted between a mobile station for wirelessly sending and/or receiving data and the base stations and broadcast messages are also forwarded between the base stations. These broadcast messages do not have an associated explicit connection between two units in the radio network. Moreover, the mobile station which receives a broadcast message can process this message regardless of the base station from which it originates. This avoids so-called 'hand offs,' which are used in the prior art to associate a mobile station with a new base station when the mobile station moves out of range of the earlier base station. These hand offs result in time delays which are unacceptable in safety-critical applications. The novel method is particularly suitable for use in traffic systems, particularly in rail traffic systems, in which, by way of example, a train is controlled via a central unit using the radio network. In such applications, it is particularly important for no relatively long delays to arise in the data transmission, since otherwise the safety of the traffic system is no longer assured.

Method for transmitting data in a wireless radio network

In a method for determining link and route metrics, in order to determine an optimal path for time-critical transmission such as video telephony or VoIP, for use in routing protocols, the route metric is calculated as the product of the link metrics, wherein the link metrics in turn are calculated from the formula L=1&#x2212;(1&#x2212;AA)^(W+1), wherein L is the link metric, Aand Aare the data packet arrival rates in the outgoing and incoming directions of a link, and W is the maximum number of retransmissions per link. The route metric is optimal for the route which has the lowest number of lost packets.

Method for determining a path distance value and network nodes

A method determines a route in distance value for use in routing protocols. An optimum route is determined for time-critical transmissions such as videotelephony or VoIP. For this purpose, the route distance value is calculated as the product of the link metrics for the links of a route, said link metrics being the product of data packet arrival rates. This value is the optimum value for the route which requires the lowest number of repeated packet transmissions (retransmissions). Optionally, an additional factor can be inserted in the link metrics, which factor ensures that the length of a route is also taken into consideration.

Method for determining a route distance value

When setting up a wireless network formed of several communication terminals, it is usual for the communication terminals to be devoid of information on local topology. In large wireless mobile environment networks it is advisable to create an independent large-network setup, wherein individual communication terminals which are not yet connected and/or partial networks are integrated. The method enables automatic dynamic, large-network organization, taking into account communication terminals which are not yet connected. This is achieved by exchanging messages between the communication devices to determine local topology information independently and by integrating the thus enhanced isolated individual communication terminals and partial networks.

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Munich, Germany

Matthias Kutschenreuter