Data transmission system with adjustable transmission power
A data transmission system has a first terminal device (H) and a second terminal device (Ni) between which data (DLi, ULi) can be transmitted via a radio link. The first terminal device (H) contains control means (S) for timed increase of the transmission power for sending data (DLi) up to a time which is determined as a result of the presence of the radio link being established.
1 . A method for establishing the necessary transmission power in a data transmission system which has a first terminal device and a second terminal device between which data are transmitted by radio, comprising the steps of:
(a) transmitting consecutive test data packets by the first terminal device, with the transmission power in the first terminal device rising in prescribed fashion over time; and
(b) transferring a reception confirmation data packet from the second terminal device to the first terminal device following reception of a test data packet, subsequently called initialization data packet, for the first time and further processing of the first initialization packet by the second terminal device, wherein the test data packets contain information about the respective transmission power which is used to transmit them.
2 . The method as claimed in claim 1 , wherein the first terminal device essentially uses a constant transmission power, following reception of the reception confirmation data packet, for transferring further data packets to the second terminal device.
3 . The method as claimed in claim 2 , wherein the first terminal device transmits the further data packets to the second terminal device essentially using the same transmission power as that which was used to transmit the initialization data packet.
4 . The method as claimed in claim 1 , wherein the transmission power which was used to transmit the initialization data packet is stored by the first terminal device.
5 . The method as claimed in claim 4 , wherein when the method has concluded and the method is started again the first terminal device transmits the first test data packet to the second terminal device using the stored transmission power.
6 . The method as claimed in claim 1 , wherein
reception of the initialization data packet prompts the second terminal device to read the information about the transmission power which was used to transmit the initialization data packet, and
the second terminal device sends the reception confirmation data packet and, in particular, further data packets to the first terminal device using the same transmission power as the transmission power used for the initialization data packet.
7 . The method as claimed in claim 1 , wherein
the data transmission system is based on the Bluetooth standard, and
the first terminal device is the primary terminal device and the second terminal device is an ancillary terminal device.
8 . The method as claimed in claim 1 , wherein the method is used while the data transmission system is being started up from the off state or at least an inactive state.
9 . A method for establishing the necessary transmission power in a data transmission system which has a first terminal device and a plurality of second terminal devices between which data are transmitted by radio, comprising the steps of:
(a) transmitting consecutive test data packets to each second terminal device by the first terminal device, with the transmission power in the first terminal device rising in prescribed fashion over time until the first device has received from each of the second terminal devices a reception confirmation data packet which has been transferred in line with method step b),
(b) transferring a reception confirmation data packet from one of the second terminal devices to the first terminal device following reception of a test data packet, subsequently called initialization data packet, for the first time and further processing of the initialization packet by the respective second terminal device, and
(c) storing the respective transmission power required for reception for each of the second devices in a table.
10 . The method as claimed in claim 9 , wherein the stored transmission power is used for later connection setup to the respective second device.
11 . The method as claimed in claim 9 , wherein the first terminal device sends further data packets to a second terminal device using a transmission power which is determined by the initialization data packet associated with this second terminal device.
12 . The method as claimed in claim 9 , wherein
the data transmission system is based on the Bluetooth standard,
the first terminal device is the primary terminal device and the second terminal devices are ancillary terminal devices, and
the primary terminal device operates in the Bluetooth-specific inquiry mode during method steps a) to c).
13 . The method as claimed in claim 9 , wherein the method is used while the data transmission system is being started up from the off state or at least an inactive state.