Browse Prior Art Database

Smart Capacity Boost

IP.com Disclosure Number: IPCOM000019473D
Original Publication Date: 2003-Oct-25
Included in the Prior Art Database: 2003-Oct-25
Document File: 3 page(s) / 193K

Publishing Venue

Siemens

Related People

Juergen Carstens: CONTACT

Abstract

In mobile radio networks the participants are transmitting information by using radio band broadcasts. The topology of the network is organized in cell units. In the same cell the transmitters are using the same radio frequency. This frequency varies from one cell to another. The radio networks have employed radio frequency power control to minimize the transmitter power to a certain level which is able to ensure adequate speech quality and to reduce the cell-to-cell interference. The control loop for power control (PC) is based on measurements of the controlled system parameters. In current radio networks the power control decision is based on the received signal quality RXQUAL, which is mapped to C/I values to get a better resolution, and the received signal level RXLEV. Both measures, signal quality and signal level, are used to keep the operational range within a predefined power control window, the center region shown in Fig. 1.

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© SIEMENS AG 2003 file: 2003J09233.doc page: 1

Smart Capacity Boost

Idea: Dr. Carsten Ball, DE-Munich; Dr. Markus Mummert, DE-Munich; Dr. Kolio Ivanov, DE-Munich;

Robert Müllner, DE-Munich; Jörg Monschau, DE-Munich; Gerhard Reisnecker, DE-Munich; Franz Treml, DE-Munich

In mobile radio networks the participants are transmitting information by using radio band broadcasts. The topology of the network is organized in cell units. In the same cell the transmitters are using the same radio frequency. This frequency varies from one cell to another. The radio networks have employed radio frequency power control to minimize the transmitter power to a certain level which is able to ensure adequate speech quality and to reduce the cell-to-cell interference.

The control loop for power control (PC) is based on measurements of the controlled system parameters. In current radio networks the power control decision is based on the received signal quality RXQUAL, which is mapped to C/I values to get a better resolution, and the received signal level RXLEV. Both measures, signal quality and signal level, are used to keep the operational range within a predefined power control window, the center region shown in Fig. 1.

In today's systems static settings are applied for the upper and lower threshold for the quality based decision and for the upper and lower threshold for the signal level based decision. If the current quality and signal level is within this power control window, the currently applied transmitter power is kept constant. In case that the current quality or signal level is higher than the corresponding upper threshold of the power control window, the transmitter power is reduced. If the current quality or signal level is lower than the corresponding lower threshold, the transmitter power is increased (Fig. 1).

The core of the new idea is a shift of the power control window to lower C/I values. This leads to a reduction of the interference in the network and will only result in a low degradation of quality. It improves the overall performance in the network.

The standard power control thresholds (static upper and lower thresholds) are automatically set to provide optimum quality whenever interference is low. As the traffic load grows the interference level increases. Now the power control thresholds are shifted towards lower quality levels. This decrease of interference can be used for increasing the capacity of the network. This means that the power control thresholds are no longer used as fixed values, as applied in previous algorithms, but they are dynamically adapted to the present quality level.

Both, upper and lower, thresholds for power control are dynamically adjusted according to one or a combination of the following triggering points:

Interference level in the network, respectively in a defined network area. The power control window in the considered cell is moved towards lower C/I values. The interfering cells reduce their tra...