WO2006059172A1

WO2006059172A1 - Method, device and system for power control in wireless communication systems using cdma-based technologies

Info

Publication number: WO2006059172A1
Application number: PCT/IB2004/003928
Authority: WO
Inventors: Guan Hao; Zhao Zhu Yan; Zheng Hong Ming
Original assignee: Nokia Inc
Current assignee: Nokia Inc
Priority date: 2004-12-01
Filing date: 2004-12-01
Publication date: 2006-06-08
Anticipated expiration: 2007-06-01

Abstract

The inventive concept relates to an enablement of outer-loop power control in data packet transmission employing physical layer error recovery mechanism. A base receiving data packets from a mobile station determines beneath the soft quality information physical channel quality information, which reflects the actual transmission channel condition experienced during data packet transmission. On the basis of that PHY CH quality information, a radio network controller is able to determine reliable target adjustments in an outer-loop power control mechanism, which target adjustments are provided to the (fast) closed-loop power control present in the base station.

Description

METHOD, DEVICE, AND SYSTEM FOR POWER CONTROL IN WIRELESS COMMUNICATION SYSTEMS USING CDMA-BASED TECHNOLOGIES

The present invention relates to Code Division Multiple Access (CDMA) technology and in particularly to Wideband Code Division Multiple Access (WCDMA) technology. More particularly, the present invention relates to an improvement in power control mechanisms.

In any Code Division Multiple Access (CDMA) system including Wideband Code Division Multiple Access (WCDMA) such as Universal Mobile Telecommunication Services / System (UMTS) power control mechanisms is of special interest in view of overall system performance. One outstanding feature of CDMA systems is the sharing of the same radio frequency at the same time for mobile stations (or user equipment) within the system and more particular within any cell. One mobile station in operation at such a high power level, i.e. at power level higher than required, is able to drawn out other mobile stations subscribed in the same cell or even in adjacent cells. The most important example regarding the importance of power control mechanisms is the so-called near-far problematic. Assume that a mobile station is located near the base station of a cell, whereas another one is located in a distance, for instance near the cell edge or cell boundary. If both mobile stations operate at the same time at the substantially same power level for radio frequency uplink transmission to the base station of the cell, the radio frequency signal from the "near located" mobile station may at least partially or substantially completely overpower the signal of the "faraway" mobile station. This results therein that the signal from the "far-away" mobile station would be unrecoverable by the base station.

Known CDMA systems implement power control mechanisms to avoid such effects; i.e. power control mechanism address power level adaptation in view of the near-far effect, fading effects on radio frequency channels (Rayleigh Fading), and quality of service (QoS) requirements and interference minimization. Typical headwords in the context of power control mechanisms are open-loop power control, (fast) closed-loop power control, and outer-loop power control, each being addressing different aspects and requirement within the wireless communication system.

Open-loop power control mechanisms attempt to make a (rough) estimation of signal path losses by means of a bacon signal in downlink (i.e. communication link from a base station / node B to a mobile station / user equipment). Those skilled in the art appreciate that the fast fading within downlink and uplink (i.e. communication link from a mobile station / user equipment link to base station / node B) communications is essentially uncorrelated due to the frequency separation of uplink and downlink frequency band. Open-loop power control mechanisms are, however, used in WCDMA to provide a coarse initial power level setting of the mobile station at the beginning of a connection.

Closed-loop power control mechanisms and in particular fast closed-loop power control mechanisms serve for better power level adaptation of the mobile station. In closed-loop power control in the uplink, the base station performs frequent estimates of the received Signal-to-Interference Ratio (SIR) and compares the received SIR to a target SIR. On the basis of this comparison, the base station instructs the mobile station to increase the power level, to maintain the power level or to decrease the power level depending whether the comparison has resulted in an exceeding, substantially equal, and falling below received SIR with regard to the threshold target SIR. The measure-command-react cycle has to accomplish the physical requirements of the channel(s) used and the capabilities of the entities (i.e. the mobile station and the base station) participating in the mechanism. Consequently, the cycle differs among specific mobile communications systems.

For example, Global System for Mobile Communications (GSM) operates closed-loop power control with a slow cycle rate of 2 Hz, whereas WCDMA system implementation provides for 1.5 kHz cycle rate in uplink as well as downlink and IS-95 (cdmaOne) implements a cycle rate of 800 Hz only in uplink. With reference to WCDMA technology, the measure-command-react cycle rate of 1.5 kHz is able to compete with any significant changes of path loss and indeed with the effective rate of Rayleigh fading at moderate speeds of mobile stations; both physical channel effects have a slower rate.

It should be noted that the motivation for closed-loop power control in downlink differs from that in uplink. It is evident that the near-far problem is not present on downlink communication. Nevertheless, mobile stations near the cell edge or cell boundary suffer in an increased level of interference from adjacent cells. Additionally, weak signals caused by Rayleigh fading experienced by mobile stations at low speeds may have to be enhanced.

Outer-loop power control mechanisms address adjustments of the setpoint of the target Signal-to-interference Ratio (SIR) in the base station according to the requirements of individual radio frequency links and aim constant Quality of Service (QoS). This means that the target SIR value applied for (fast) closed-loop power control mechanisms is a function of the required quality for the service to be supported. For instance, if the quality of service would be a measure in terms of Frame Error Rate (FER) on the air interface (as determined on the basis of a Cyclic Redundancy Check (CRC)), then the target SIR can be considered a function of FER. Whereas a closed-loop power control mechanism is typically implemented as a function of a base station, an outer-loop power control mechanism is implemented as a function of a (serving) Radio Network Controller (RNC), which receives quality indications from the base station in form of transmission quality measures relating to the air interface (such as the FER, CRC etc.). The RNC commands the setting of the target SIR setpoint on the basis of the received quality indications. The reason for having outer-loop control mechanism implemented in the RNC is that this function should be available during and/or after soft handover combining. The outer-loop power control cycle is typically about 10 — 100 Hz

The increasing capabilities and functionalities of mobile stations promote the desire to offer multifunctional mobile stations having features, which are typically inherent in today's terminal stations having a wire-based network connection for data communication. The widespread use of Internet Protocol (IP) based services and in particular Transmission Control Protocol (TCP) based services is characteristic for data communication within today's local area networks (LAN) and wide area networks (WAN) such as the Internet. Efforts are under development to migrate services available over the Internet to wireless networks and especially to the third generation wireless networks being currently introduced in the mass market. Network operators and service providers operating in the field of enhanced second generation and third generation wireless networks, respectively, hope for benefiting from the high data rate packet services operable with these wireless networks in that services available up to now merely wire-based might be migrated to wireless networks presenting itself new economic opportunities. Typical applications, which benefit from high data rates, include video-clips, multimedia, e-email, telematics, gaming, video-streaming etc.

One main aspect of the Transmission Control Protocol (TCP), which represents the dominant transmission protocol in today's wire-based networks, is its well-designed flow and congestion control mechanism, which were introduced under the assumption that packet losses are due to network congestion only. However, wireless networks such as UMTS (universal mobile telecommunications system) are not reliable, i.e. the wireless networks are characterized by high bit and block error rates resulting in packet losses. To overcome the disadvantages of packet losses, which are not acceptable in conjunction with a huge number of applications, low layer protocols employed for instance by the WCDMA/UMTS make use of error recovering mechanisms. One major class of error recovery mechanisms is formed by the Automatic Repeat Request (ARQ) mechanisms.

The potential of Automatic Repeat Request (ARQ) is being studied as one potential mechanism to improve the performance of WCDMA uplink in UMTS, which locates between base station (Node B) and mobile station (user equipment, UE). Moreover, physical Automatic Repeat Request (PHY ARQ) mechanism enables to shield the error recovering from upper layer as much as possible in that the error recovering in accordance with ARQ is preferably provided as physical layer mechanism implemented as a function of the base station.

It should be understood that Automatic Repeat Request (ARQ) mechanisms is a generic term and are based on different protocol structures resulting in different ARQ processes, comprising for instance Stop-and-Wait (SAW), Concurrent Logical Channels (CLC), Go- back-N, and Selective-Repeat. A subclass of Automatic Repeat Request (ARQ) mechanisms is designated as Hybrid Automatic Repeat Request (HARQ) mechanisms.

In general, the base station (Node B) controlled ARQ mechanisms allow for rapid retransmissions of erroneously received data, thus reducing the number of radio link control (RLC) retransmissions and the associated delays. The ARQ mechanisms can improve the quality of service (QoS) experienced by the user of the mobile terminal (UE). As a base station controlled retransmission is less costly from the view of a delay in time, physical channels, i.e. physical uplink channels, are operable with higher error probability, which may result in improved system capacity. The retransmission probability for the initial transmission is preferably in the order of 10 - 20 %, when evaluating the employed ARQ mechanism as closed loop power control is used for the uplink, maintaining a given quality level in accordance with predefined quality of service (QoS) requirements. Significantly higher retransmission probabilities may lead to considerably reduce the throughput experienced by the user of the mobile terminal (UE), while at very small retransmission probabilities the base station (Node B) controlled ARQ mechanisms will not provide any additional gains.

With reference to 3^rd Generation Partnership Project (3 GPP) specification Release 1999, the outer loop power control in uplink is to keep the quality of communication at the required level by setting target SIR setpoint for the fast open-loop power control as described above.

The RNC commands the adjustment of the target SIR for the fast open-loop power control on the basis of a measured quality of communication and a target quality of communication.

Here the target SIR is adjusted by RNC based on physical (PHY) link quality such as Frame Error Rate (FER), Bit Error Rate (BER), signal energy per bit divided by noise spectral density (Eb/NO), Cyclic Redundancy Check (CRC), etc.

Assume that any physical Automatic Repeat Request (PHY ARQ) or any physical Hybrid

Automatic Repeat Request (PHY HARQ) is implemented on the Radio Link Control (RLC) Layer in the base station (Node B). By introducing an error recovering mechanism on the basis of a PHY ARQ/HARQ mechanism, the physical (PHY) link quality could be significantly improved. However, such an error recovery mechanism will evade the outer loop power control mechanism implemented in the RNC, which receives quality indications from the base station (Node B) for commanding the target SIR on the basis of a quality adjustment as described above. The base station (Node B) reports "fake" information to the RNC that the physical channel condition is good due to the performing of an ARQ/HARQ mechanism. For RNC point of view, the ARQ/HARQ mechanism covers bad physical channel quality. Consequently, the outer-loop power control mechanism can not be operated as originally intended.

Therefore, the object of the present invention is to provide a concept for outer-loop power control mechanisms enabling interoperability with any physical Automatic Repeat Request (PHY ARQ) mechanism, especially in uplink from a mobile terminal to a base station (Node B). Particularly, the object of the present invention is to provide a concept to establish an adequate signaling between base station (Node B) performing PHY ARQ/HARQ mechanisms and RNC performing outer-loop power control mechanisms.

The object of the present invention is solved by introducing an improved signaling between the base station (Node B) and the RNC, the base station (Node B) and the RNC adapted to the improved signaling and methods operable with the base station (node B) and the RNC, respectively..

According to a first aspect of the present invention, a method for a base station of enabling outer-loop power control in data packet transmission employing error recovery mechanism is provided. The error recovery mechanism is in particular a physical layer error recovery mechanism. Via an air interface of the base station one or more data packets are received from a mobile station. The receiving of the data packets is operable with the error recovery mechanism, which results in error recovered data packets. A physical channel quality detection entity of the base station serves for determining physical channel (PHY CH) quality information. The PHY CH quality information comprises one or more different physical channel quality values, each of which reflects the actual physical condition of a channel, on which the data packets have been transmitted from the mobile station to the base station. Particularly, the PHY CH quality information is independent of a quality of said error recovered data packets. A data interface of the base station enables to communicate with a radio network controller. A set or record is transmitted to the radio network controller. The record includes at least the error recovered data packets, the soft quality information, and the physical channel quality information to a radio network controller. Subsequently, a target adjustment command is received from the radio network controller. The target adjustment command instructs an adjustment of a target value operable with a closed-loop power control mechanism operable with the base station. The closed-loop power control mechanism generates transmit power control (TPC) commands to instruct the mobile station to adjust its transmission power level for data transmission to the base station.

According to an embodiment of the present invention, the error recovered data packet is obtained by combining an original and one or more retransmit data packets in accordance with the error recovery mechanism. The original data packets are received with a first transmission and the retransmit data packets are received with n-th retransmissions subsequent to the first transmission and instructed by a signaling of the error recovery mechanism to the mobile station.

According to another embodiment of the present invention, the physical channel quality information is obtained on the basis of an original data packet received with the first transmission.

According to yet another embodiment of the present invention, the physical channel quality information comprises cyclic redundancy check, received signal energy per bit divided by noise spectral density; frame error rate and/or bit error rate.

According to a further embodiment of the present invention, the error recovery mechanism is an Automatic Repeat Request (ARQ) mechanism or a Hybrid Automatic Repeat Request (HARQ) mechanism. According to yet a further embodiment of the present invention, a channel decoder entity of the base station determines soft quality information from the error recovered data packets. The set to be transmitted to the radio network controller includes additionally the soft quality information, which is in particular provided to the radio network control operable in soft handover.

According to an additional embodiment of the present invention, the base station is operable with a cellular Public Land Mobile Network (PLMN). In particular the base station is operable with a cellular mobile communication network supporting Code Division Multiple Access (CDMA) -based technology. More particularly, the base station is operable with a wideband code division multiple access system such as Universal Mobile Telecommunication System (UMTS).

According to a second aspect of the present invention, a method for a radio network controller of enabling outer-loop power control in data packet transmission employing error recovery mechanism is provided. The error recovery mechanism is in particular a physical layer error recovery mechanism. Via a data interface a first set or record is received for a first base station. The first set or record comprises at least one or more error recovered data packets and physical channel quality information. The physical channel quality information of the first set includes one or more physical channel quality values, which are adequate to reflect or represent the actual physical condition of a channel on which the data packets have been originally transmitted by the mobile station to the first base station. Particularly, the PHY CH quality information is independent of a quality of said error recovered data packets. An outer-loop power control entity provided for determining a target adjustment on the basis of one quality value obtained from the physical channel quality information of the first set in relation to a pre-determined target quality of service value. A target adjustment command on the basis of the target adjustment is transmitted by the means of the data interface to the base station to enable an adjustment of a target value of a closed-loop power control mechanism, which is operable with the first base station and instructive to the mobile terminal. According to an embodiment of the present invention, the physical channel quality information comprise cyclic redundancy check, received signal energy per bit divided by noise spectral density; frame error rate; and/or bit error rate.

According to another embodiment of the present invention, the error recovered data packet is obtained on base station side by applying an error recovery mechanism, in particular an ARQ/HARQ mechanism.

According to yet another embodiment of the present invention, a second set (or record) is received via the data interface from a second base station. The second set or record comprises at least one or more error recovered data packets, and physical channel quality information. Analogously, the physical channel quality information of the second set includes one or more physical channel quality values, which represent or reflect essentially adequately the actual physical condition of a channel on which the data packets have been originally transmitted by the mobile station and received by the second base station. Particularly, the PHY CH quality information is independent of a quality of said error recovered data packets. The data packets of the first set and the second set have been received essentially concurrently by the first base station and the second base station. This means that the data packets of the first set and the second set relate to the same content. In particular, the data packets are received in soft handover operated by the radio network controller. The quality value is determined by the means of a physical channel quality evaluation entity. In particular, the quality value is determined by considering the physical channel quality information included in the first set and the physical channel quality information included in the second set. A target adjustment command is transmitted via the data interface to the second base station. The second base station and in particular a closed-loop power control mechanism operable with the second base station is enabled for adjusting a target value on the basis of the received target adjustment command.

According to a further embodiment of the present invention, the quality value is determined by the on the basis of a relationship, which considers one or more physical channel quality values of the physical channel quality information of the first set and one or more physical channel quality values of the physical channel quality information of the second set.

According to yet a further embodiment of the present invention, the relationship is a function of a physical channel quality value included in the physical channel quality information of the first set and physical channel quality value included in the physical channel quality information of the second set. In particular the relationship is minimum function, which result is the minimal value out of a plurality of values (including that minimal value).

According to an additional further embodiment of the present invention, the first and/or the second set each include additionally soft quality information, which represent a quality of said error recovered data packets. The soft quality information is in particular provided to enable soft handover handled by the radio network controller.

According to yet an additional embodiment of the present invention, the radio network controller is operable with a cellular Public Land Mobile Network (PLMN). In particular the radio network controller is operable with a cellular mobile communication network supporting Code Division Multiple Access (CDMA) -based technology. More particularly, the radio network controller is operable with a wideband code division multiple access system such as Universal Mobile Telecommunication System (UMTS).

According to a third aspect of the present invention, computer program is provided. The computer program comprises program code sections for carrying out the method according to an aforementioned embodiment of the invention, when the program is run on a controller, processor-based device, a computer, a terminal, a network device, a mobile terminal, or a mobile communication enabled terminal.

According to a fourth aspect of the invention, a computer program product is provided, which comprises program code sections stored on a machine-readable medium for carrying out the steps of the method according to an aforementioned embodiment of the invention, when the computer program product is run on a controller, processor-based device, a computer, a terminal, a network device, a mobile terminal, or a mobile communication enabled terminal. Alternatively, an application specific integrated circuit (ASIC) may implement one or more instructions that are adapted to realize the aforementioned operations of the method according to an embodiment of the invention, i.e. equivalent with the aforementioned computer program and computer program product, respectively .

According to a fifth aspect of the invention, a computer data signal embodied in a carrier wave and representing instructions is provided which when executed by a processor cause the operations of the method according to an embodiment of the invention to be carried out.

According to a sixth aspect of the present invention, a base station device enabling outer-loop power control in data packet transmission employing error recovery mechanism is provided. The error recovery mechanism is in particular a physical layer error recovery mechanism. The base station device comprises an air interface for communication with a mobile station, a physical channel quality detection entity, and a data interface for communicating with a radio network controller device. One or more data packets are received by the means of the air interface. The reception of the data packets is supported by the error recovery mechanism, the application of which results to error recovered data packets. A physical channel quality detection entity is provided to determine physical channel quality information including one or more physical channel quality values. The physical channel quality values are obtained to reflect the actual physical condition of a channel, on which the data packets have been originally transmitted by the mobile station and received by the base station device. Particularly, the PHY CH quality information is independent of a quality of said error recovered data packets. A set or record including the error recovered data packets and the physical channel quality information is formed and transmitted via the data interface to a radio network controller device. A target adjustment command is received via the data interface from the radio network controller device in consequence to the transmission. The target adjustment command instructs to adjust a target value used in a closed-loop power control mechanism operable with the base station device and instructive to the mobile station device for transmit power control thereof. According to an embodiment of the present invention, the base station device comprises additionally a channel decoder entity. On the basis of the error recovered data packets resulting from the error recovery mechanism, the channel decoder entity determines soft quality information, which represents essentially the quality of the error recovered data packets, in particular in view of erroneous contents thereof due to over air transmission. The soft quality information is applicable for soft handover operable with the radio network controller device.

According to another embodiment of the present invention, the base station device is operable with a cellular public land mobile network and in particular with a cellular mobile communication network supporting Code Division Multiple Access (CDMA) -based technology. More particularly, the base station device is operable with a Wideband Code Division Multiple Access (WCDMA) system and especially with Universal Mobile Telecommunication System (UMTS).

According to yet another embodiment of the present invention, the base station device is adapted to perform operations of the method according to any embodiment of the present invention described above in detail.

According to a seventh aspect of the present invention, a radio network controller device enabling outer-loop power control in data packet transmission employing error recovery mechanism is provided. The error recovery mechanism is in particular a physical layer error recovery mechanism. The radio network controller device comprises a data interface for communication with base stations and an outer-loop power control entity. A first set or record is received from a first base station device. The first set (or record) includes at least one or more error recovered data packets and physical channel quality information. The physical channel quality information of the first set includes one or more physical channel quality values. The physical channel quality values are adequate to reflect or represent the actual physical condition of a channel, on which the data packets have been originally received by the first base station device. Particularly, the PHY CH quality information is independent of a quality of said error recovered data packets. The outer-loop power control entity is enabled to determine a target adjustment on the basis of one quality value obtained from the physical channel quality information of the first set and a pre-determined target quality of service value. A target adjustment command generated on the basis of the determined target adjustment is transmitted to the first base station device. The target adjustment command instructs a closed-loop power control mechanism operable with the first base station device to adjust a target value.

According to an embodiment of the present invention, a second set or record is received via the data interface from a second base station device. Analogously, the set (or record) includes one or more error recovered data packets and physical channel quality information. The physical channel quality values are adequate to reflect or represent the actual physical condition of a channel, on which the data packets have been originally received by the second base station device. Particularly, the PHY CH quality information is independent of a quality of said error recovered data packets. The data packets of the first set and the second set have been received essentially concurrently by the first base station device and the second base station device and have the same content when omitting possible (bit) errors present therein. This means that the data packets of the first set and the second set relate to the same content. In particular, the data packets are received in soft handover. The physical channel quality information of the second set includes one or more physical channel quality values. The physical channel quality values are adequate to reflect or represent the actual physical condition of a channel, on which the data packets have been originally received by the second base station device. The physical channel quality evaluation entity allows determining the quality value by considering the physical channel quality information included in the first set as well as the physical channel quality information included in the second set. The target adjustment command is transmitted via the data interface to the second base station device. The target adjustment command instructs to adjust a target value used in a closed-loop power control mechanism operable with the base station device and instructive to the mobile station device for transmit power control thereof.

According to another embodiment of the present invention, the first and/or the second set each include additionally soft quality information, which represent a quality of said error recovered data packets. The soft quality information is in particular provided to enable soft handover handled by the radio network controller.

According to yet another embodiment of the present invention, the radio network controller device is operable with a cellular public land mobile network and in particular with a cellular mobile communication network supporting Code Division Multiple Access (CDMA) -based technology. More particularly, the network controller device is operable with a Wideband Code Division Multiple Access (WCDMA) system and especially with Universal Mobile Telecommunication System (UMTS).

According to yet another embodiment of the present invention, the radio network controller device is adapted to perform operations of the method according to any embodiment of the present invention described above in detail.

According to an eighth aspect of the present invention, a system is provided which includes at least a first base station device and a radio access network controller device, which are part of a Radio Network Subsystem (RNS), which enables outer-loop power control in data packet transmission employing error recovery mechanism. The error recovery mechanism is in particular a physical layer error recovery mechanism.

The first base station device comprises an air interface for communication with a mobile station, a physical channel quality detection entity, and a data interface for communicating with a radio network controller device. One or more data packets are received by the means of the air interface of the first base station device. The reception of the data packets is supported by the error recovery mechanism, the application of which results to error recovered data packets. The physical channel quality detection entity of the first base station device is provided to determine physical channel quality information including one or more physical channel quality values. The physical channel quality values are obtained to reflect the actual physical condition of a channel, on which the data packets have been originally transmitted by the mobile station and received by the first base station device. Particularly, the PHY CH quality information is independent of a quality of said error recovered data packets. A first set or record including the error recovered data packets and the physical channel quality information is formed and transmitted via the data interface of the first base station device to a radio network controller device.

The radio network controller device comprises a data interface for communication with base stations and an outer-loop power control entity. The first set or record is received from the first base station device. The outer-loop power control entity of the radio network controller device is enabled to determine a target adjustment on the basis of one quality value obtained from the physical channel quality information of the first set and a pre-determined target quality of service value. A target adjustment command generated on the basis of the determined target adjustment is transmitted from the radio network controller device to the first base station device.

The target adjustment command is received via the data interface of the first base station device from the radio network controller device in consequence to the transmission of the first set (or record). The target adjustment command instructs to adjust a target value used in a closed-loop power control mechanism operable with the first base station device. The closed-loop power control mechanism of the first device is instructive to the mobile station device for transmit power control thereof.

According to an embodiment of the present invention, the system comprises a second base station device. The second base station device comprises in analogy to the first base station device an air interface for communication with a mobile station, a physical channel quality detection entity, and a data interface for communicating with a radio network controller device. One or more data packets are received by the means of the air interface of the second base station device. The reception of the data packets is supported by the error recovery mechanism, the application of which results to error recovered data packets. A physical channel quality detection entity of the second base station device is provided to determine physical channel quality information including one or more physical channel quality values. The physical channel quality values are obtained to reflect the actual physical condition of a channel, on which the data packets have been originally transmitted by the mobile station and received by the second base station device. Particularly, the PHY CH quality information is independent of a quality of said error recovered data packets. A second set or record including the error recovered data packets and the physical channel quality information is formed and transmitted via the data interface of the second base station device to a radio network controller device.

The second set (or record) is received via the data interface of the radio network controller device from the second base station device. The data packets of the first set and the second set have been received essentially concurrently by the first base station device and the second base station device and have the same content when omitting possible (bit) errors present therein. This means that the data packets of the first set and the second set relate to the same content. In particular, the data packets are received in soft handover operation of the mobile station in conjunction with the first and second base station devices and controller by the radio network controller device. The physical channel quality evaluation entity of the radio network controller device allows determining the quality value by considering the physical channel quality information included in the first set as well as the physical channel quality information included in the second set. The target adjustment command is also transmitted via the data interface of the radio network controller device to the second base station device.

The target adjustment command is received via the data interface of the second base station device from the radio network controller device in consequence to the transmission of the second set (or record). The target adjustment command instructs to adjust a target value used in a closed-loop power control mechanism operable with the second base station device. The closed-loop power control mechanism of the second device is instructive to the mobile station device for transmit power control thereof.

According to another embodiment of the present invention, on the basis of the error recovered data packets resulting from the error recovery mechanism, a channel decoder entity of the first base station device determines soft quality information, which represents essentially the quality of the error recovered data packets, in particular in view of erroneous contents thereof due to over air transmission from the mobile station to the first base station device. Alternatively or additionally, a channel decoder entity of the second base station device determines on the basis of the error recovered data packets resulting from the error recovery mechanism soft quality information, which represents essentially the quality of the error recovered data packets, in particular in view of erroneous contents thereof due to over air transmission from the mobile station to the first base station device. The first and/or the second set to be transmitted to the radio network controller device each include additionally the soft quality information.

According to yet another embodiment of the present invention, the first and/or second base station device of the system corresponds to the base station device according to any embodiment of the present invention described above in detail. The radio network controller device of the system corresponds to the radio network controller device according to any embodiment of the present invention described above in detail. In Particularly, the first base station device, the second base station device, and/or the radio network controller device are adapted to perform operations of the method according to any embodiment of the present invention described above in detail.

The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:

Fig. 1 illustrates a schematic block diagram of a mobile station transmitting data via an uplink to a radio network subsystem (RNS) comprising a base station (Node B) and a Radio Network Controller (RNC) implementing an outer-loop power control (PC) mechanism according to an embodiment of the present invention;

Fig. 2 illustrates a schematic block diagram in analogy to Fig. 1, but the mobile station is operating in soft handover (SHO) on the basis of macro diversity combining implemented in the RNC according to another embodiment of the invention;

Fig. 3 illustrates a schematic sequence chart, illustrating the operations of the participating network entities of Fig. 1 according to an embodiment of the present invention; and Fig. 4 illustrates a schematic sequence chart, illustrating the operations of the participating network entities of Fig. 2 according to an embodiment of the present invention.

With reference to Fig. 1, a data transmission via an uplink from the mobile terminal 1 (user equipment, UE) to the Radio Network Subsystem (RNS) including a base station (Node B) 2 and a (serving) Radio network controller (RNC) 4 should be illustrated.

First assuming the conventional case, where an error recovery mechanism on the basis of an ARQ / HARQ mechanism is not implemented. The base station (Node B) 2 receives data packets transmitted from the mobile station (UE) 1 via the Uu Interface, i.e. the air interface, decodes the data by the means of a channel decoder 20 and sends the decoded data to the RNC 4 together with Cyclic Redundancy Check (CRC) and further soft quality information like received signal energy per bit divided by noise spectral density (Eb/E0), Frame Error Rate (FER)₅ Bit Error Rate (BER), etc to the RNC 4 via the Iub Interface. The latter quality information values represent frame reliability information. The RNC collects this soft quality information representing the data quality of the data packets received by the base station (Node B) 2 via the Uu interface from the mobile station (UE) 1. The outer-loop PC mechanism 41 implemented in the RNC 4 is adapted to SIR target adjustment commands preferably on the basis of the Cyclic Redundancy Check (CRC) and/or the further soft quality information denoted exemplarily above. The adjustment of the target SIR and/or further target values is based on an algorithm; an example algorithm is illustratively presented below on the basis of a pseudo code:

IF CRC check OK

Step_down = FER__target * Step_size; SIR_target(n+l) = SIR_target(n) - Steρ_down; ELSE

Step_up = Step_size - FER_target * Step_size; SIR_target(n+l) = SIR_target(n) + Steρ_uρ;

END where SIR_target(n) is the target SIR in frame n and FER_target is the target FER for the link and Step_size is a predefined parameter, typically 0.3 to 0.5 dB.

The target FER represents one of the applicable predefined target Quality of Service values, which is assumed to be optimal, adequate and/or required for the data transmission in uplink. In more detail, the assessment of an optimal, adequate, and/or required target Quality of Service value depends on the kind of service for which the transmitted data in uplink is associated. Data services such as speech service, video service, web service etc. may have assigned different target Quality of Service value.

The determined target SIR is commanded to the base station (Node B) 2, which adjusts the target SIR currently valid for (fast) closed-loop PC mechanism 23 to the commanded target SIR, which (fast) closed-loop PC mechanism 23 performs the closed-loop PC scheme on the basis of the new commanded target SIR. In accordance with the closed-loop PC mechanism 23 implemented in the base station (Node B) 2, the mobile station (UE) 1 receives one or more transmit power control (TPC) commands from the closed-loop PC mechanism 23, which are generated on the basis of the current SIR in uplink measured by the base station (Node B) 2 and the target SIR commanded by the RNC 4. Such a TPC command instructs a power controller 11 of the mobile station (UE) 1 to increase or decrease the transmission power level currently used for radio frequency signal transmission in uplink. The increasing and decreasing may be performed on the basis of a predefined power level step or power level offset, wherein the transmission power level is limited for variation within an upper signal power boundary and a lower signal power boundary.

Alternatively to the above presented illustrative outer-loop PC algorithm, which results in a target SIR, an outer-loop PC algorithm may also result in commands to increase or decrease the target SIR, which commands are send from the RNC 4 to the base station (Node B) 2, which increases or decreases accordingly the target SIR setpoint accordingly. In accordance with the concept of the present invention, it should be assumed that an error recovery mechanism on the basis of an ARQ / HARQ mechanism is implemented. In principle, the use of ARQ mechanisms and processes affect multiple layers, i.e. the coding and soft combining/decoding is handled by the physical layer, while the retransmission protocol is handled by a MAC entity located in the base station (Node B) 2 and a corresponding entity located in the mobile terminal (UE) 1. Typically Acknowledgment (ACK) / Non-Acknowledgment (NACK) signaling and retransmissions are operated in the context of the ARQ / HARQ mechanism. As aforementioned, associated control signaling required for the operation an ARQ scheme consists of downlink and uplink signaling. Downlink signaling consists typically of a single 1-bit Acknowledgement / Non- Acknowledgement (ACK/NACK) information from the base station (Node B) 2 to the mobile terminal (UE) 1. A well-defined processing framework from the reception of a data transport block at the base station (Node B) to the transmission of the (ACK/NACK) signaling in the downlink is usually used in order to avoid explicit signaling of the ARQ process number along with the (ACK/NACK) signaling. The information needed by mobile terminal (UE) 1 necessary to operate the ARQ/HARQ scheme is either explicitly signaled by the base station (Node B) 2, or decided by the mobile terminal (UE) 1 itself, depending on the ARQ/HARQ scheme employed. Uplink signaling relates to necessary information needed by the base station (Node B) 2 to operate the employed ARQ/HARQ scheme, which uplink signaling may be grouped into out-band signaling and in-band signaling. Depending on the employed ARQ/HARQ scheme considered, parts of the information might either be explicitly signaled or implicitly deduced. Nevertheless, the detailed operation of ARQ/HARQ schemes is out of the scope of the present invention.

The present inventive concept addresses modifications in the base station (Node B) 2 as well as the RNC 4 in comparison with their conventional operations illustrated above.

The base station (Node B) 2 receives data packets transmitted from the mobile station (UE) 1 and decodes the data by the means of the channel decoder 20. The channel decoder determines in a conventional way the Cyclic Redundancy Check (CRC) and the further soft quality information like received signal energy per bit divided by noise spectral density (Eb/EO), Frame Error Rate (FER), Bit Error Rate (BER), etc to the RNC 4 via the Iub Interface. In accordance with the employed ARQ/HARQ mechanism 21, the reception and decoding of the data packets from the mobile station (UE) 1 at the base station (Node B) 2 may includes one or more retransmissions from the mobile station (UE). The original data packet (of the first transmission) and the one or more retransmissions in accordance with NACK signaling of the base station (Node B) 2 to the mobile station (UE) 1 are combined for error recovery.

The soft quality information is determined on the basis of the combined data packets and the data packet quality resulting after applying the ARQ/HARQ mechanism. Consequently, the soft quality information might not reflect the actual physical channel condition(s). The soft quality information may feign physical channel conditions better than actual present, i.e. the soft quality information are not reliable. In consequence to this fact, the base station (Node

B) 2 implements a physical channel quality detection mechanism 22, which determines physical channel (PHY CH) quality information reflecting the actual physical channel condition(s), i.e. the conditions or quality of the uplink data channel of the air (Uu) interface used for data uplink.

In particular, the PHY CH quality information can be determined formed of quality values known from the soft quality information. More particularly, the PHY CH quality information may be determined on the basis of the original data packet before combining with the one or more retransmissions (received in consequence of NACK signaling in accordance with the

ARQ/HARQ mechanism 21). Thus, the PHY CH quality information may include first

Cyclic Redundancy Check (CRC_1) and further soft quality information like first received signal energy per bit divided by noise spectral density 1 (Eb/E0_l), first Frame Error Rate

(FER_1), first Bit Error Rate (BER_1), etc determined on the basis of the original data packets (of the first transmission).

Then, the base station (Node B) 2 sends the decoded data together with the soft quality information and the PHY CH quality information to the RNC 4. The RNC 4 collects this soft quality information and PHY CH quality information. The first information represents the data quality of the data packets after ARQ/HARQ operation; whereas the latter information represents the data quality of the original data packets (of the first transmission) received by the base station (Node B) 2 via the Uu interface from the mobile station (UE) 1. The outer- loop PC mechanism 41 implemented in the RNC 4 is adapted to generate SIR target adjustment commands to be sent to the base station (Node B) 2.

In contrast to the conventional operation of the outer-loop PC mechanism 41 described above, the generation of the SIR target adjustment commands can now be based on the PHY CH quality information, in particular the first Cyclic Redundancy Check (CRC_1), the first Frame Error Rate (FER_1) and the like. The algorithm for adjusting the target SIR and/or further target values can be based on the (same) conventionally implemented algorithm such as that illustrated above by the means of pseudo code.

The determined SIR target adjustment command is then communicated to the base station (Node B) 2 to adjust the target SIR currently valid for (fast) closed-loop PC mechanism 23.

In accordance with the closed-loop PC mechanism 23 implemented in the base station (Node

B) 2, the mobile station (UE) 1 receives one or more transmit power control (TPC) commands from the closed-loop PC mechanism 23, which are generated on the basis of the current SIR in uplink measured by the base station (Node B) 2 and the target SIR commanded by the RNC 4.

While the description above relates to a simple mobile station to base station communication, the following description relates to soft handover situation, where one mobile station communicates to two base stations in uplink.

During soft handover (SHO), a mobile station in an overlapping cell coverage area of two sectors belonging to different base stations, communications between mobile station and base stations take place concurrently via two air interface channels from each base station separately. In uplink direction the uplink code channel of the mobile station is received from both base stations and the received data is routed to the RNC for combining. This could be typically done so that the same frame reliability indicator (soft quality information) as provided for conventional outer-loop power control mechanism is used to select the better frame between the two possible candidates within the RNC. This selection is operated at a predefined period. The need for soft handover results from similar reasons as for closed-loop power control. Without soft handover, there would be an analogous near-far scenario of a mobile station penetrating from one cell deeply into an adjacent cell without being power- controlled by the latter. Very fast and frequent hard handovers could largely avoid this problem. However, hard handovers can be executed only with certain delays in time during which the near-far problem is present. AU the base stations in the active set send an independent power control (TPC) command to the mobile station to control the uplink transmission power level. Due to the fact that one base station of the set receiving a correct uplink signal is enough, the mobile station can lower its transmission power in consequence to one base station sending a power-down TPC command. The mobile station may apply maximal ratio combining to the data bits in soft handover. But it should be noted that the TPC commands from different base station contain different bits and cannot be combined. This means that the reliability of the TPC commands is not as good as for data bits being combinable. A threshold in the mobile station is used to check the reliability of the received TPC commands. Very unreliable power control commands should be discarded due to corruption by interference.

With reference to Fig. 2, a data transmission via an uplink from the mobile terminal (user equipment, UE) 1 to the Radio Network Subsystem (RNS) including a first base station (Node B) 2, a second base station (Node B) 3, and a (serving) Radio network controller (RNC) 4 should be illustrated. The mobile terminal 1 (UE) 1 operates in soft handover (SHO) as described above.

Components of the mobile station 1 and the base station (Node B) 2 illustrated in Fig. 1 are also present in the mobile station 1 and the first and second base stations (Node B) 2, 3 illustrated in Fig. 2. The omission of the component illustration in Fig. 2 has been done for the sake of simplicity and hence, not to limit the scope of the invention. In accordance with the inventive concept, an error recovery mechanism on the basis of an ARQ / HARQ mechanism is implemented. In principle, the use of ARQ mechanisms and processes affect multiple layers, i.e. the coding and soft combining/decoding is handled by the physical layer, while the retransmission protocol is handled by a MAC entity located in the first and second base stations (Node B) 2, 3 and a corresponding entity located in the mobile terminal (UE) 1. Typically Acknowledgment (ACK) / Non- Acknowledgment (NACK) signaling and retransmissions are operated in the context of the ARQ/HARQ mechanism. As aforementioned, associated control signaling required for the operation an ARQ scheme consists of downlink and uplink signaling. Downlink signaling consists typically of a single 1-bit Acknowledgement / Non- Acknowledgement (ACK/NACK) information from the first base station (Node B) 2 or the second base station (Node B) 3 to the mobile terminal (UE) 1. A well-defined processing framework from the reception of a data transport block at the base station (Node B) to the transmission of the (ACK/NACK) signaling in the downlink is usually used in order to avoid explicit signaling of the ARQ process number along with the (ACK/NACK) signaling. The information needed by mobile terminal (UE) 1 necessary to operate the ARQ/HARQ scheme is either explicitly signaled by the first base station (Node B) 2 and the second base station (Node B)3, respectively, or decided by the mobile terminal (UE) 1 itself, depending on the ARQ/HARQ scheme employed. Uplink signaling relates to necessary information needed by the base station (Node B) 2 and the base station (Node B) 3 to operate the employed ARQ/HARQ scheme, which uplink signaling may be grouped into out-band signaling and in-band signaling. Depending on the employed ARQ/HARQ scheme considered, parts of the information might either be explicitly signaled or implicitly deduced.

The first base station (Node B) 2 and the second base station (Node B) 3 receive concurrently data packets transmitted from the mobile station (UE) 1 and decode the data by the means of the channel decoders 20. The channel decoders 20 determine in a conventional way the Cyclic Redundancy Check (CRC) and the further soft quality information like received signal energy per bit divided by noise spectral density (Eb/E0), Frame Error Rate (FER), Bit Error Rate (BER), etc to the RNC 4 via the Iub Interface. In accordance with the employed ARQ/HARQ mechanisms 21, the reception and decoding of the data packets from the mobile station (UE) 1 at the first and second base stations (Node B) 2, 3 may includes one or more retransmissions from the mobile station (UE) to the first and second base stations (Node B) 2, 3, respectively. The original data packet (of the first transmission) and the one or more retransmissions in accordance with NACK signaling of the first and second base stations (Node B) 2, 3, respectively, to the mobile station (UE) 1 are combined for error recovery. Each of the first and second base stations (Node B) 2, 3 decodes and, if necessary, applies ARQ/HARQ mechanism independently for each other and of its own.

Analogously, the soft quality information is determined on the basis of the combined data packets and the data packet quality resulting after applying the ARQ/HARQ mechanisms. Each of the base stations (Node B) 2 and 3 determines its own set of soft quality information. As aforementioned, the soft quality information might not reflect the actual physical channel condition(s) and may feign physical channel conditions better than actual present. Each of the first and second base stations (Node B) 2, 3 implements a physical channel quality detection mechanism 22, which determines physical channel (PHY CH) quality information reflecting the actual physical channel condition(s), i.e. the conditions or quality of the uplink data channel of the air (Uu) interface used for data uplink to the first base station (Node B) 2 and the second base station (Node B) 3, respectively. In particular, the PHY CH quality information can be determined formed of quality values known from the soft quality information. More particularly, the PHY CH quality information may be determined on the basis of the original data packet before combining with the one or more retransmissions (received in consequence of NACK signaling in accordance with the ARQ/HARQ mechanism 21). An enumeration of exemplary PHY CH quality information values is described above with reference to Fig. 1.

In summary, the first base station (Node B) 2 sends the decoded data together with the first set of the soft quality information (set 1) and the first set of PHY CH quality information (set 1) to the RNC 4. Analogously, the second base station (Node B) 3 sends the decoded data together with the second set of the soft quality information (set 2) and the second set of PHY CH quality information (set 2) to the RNC 4. The RNC 4 collects the received data and information, the decoded data of the first and second base station (Node B) 2 and 3 and the first and second sets of soft quality information (set 1 and set 2) and PHY CH quality information (set 1 and set 2). The soft quality information represents the data quality of the data packets after ARQ/HARQ procedure; i.e. the first set of the soft quality information (set 1) relate to the data quality experienced by the first base station (Node B) 2 and the second set of the soft quality information (set 2) relate to the data quality experienced by the second base station (Node B) 3. The PHY CH quality information represents the data quality of the original data packets (of the first transmission) received by the first base station (Node B) 2 and the second base station (Node B) 3 via the Uu interface from the mobile station (UE) 1; i.e. the first set of the PHY CH quality information (set 1) relate to the data quality of the original data packets experienced by the first base station (Node B) 2 and the second set of the PHY CH quality information (set 2) relate to the data quality of the original data packets experienced by the second base station (Node B) 3.

The decoded data from the first base station (Node B) 2 and the decoded data from the second base station (Node B) 3 is supplied to the macro diversity combining mechanism 40 implemented in the RNC 4, which combines the received decoded data. The combining takes advantages of the two independently decoded set of data representing identical data content. This means that combining of the decoded data from the first and second base stations (Node B) 2, 3 can take advantage of an improved Signal-to-Interference Ratio (SIR). Alternatively, that decoded data with the better Signal-to-Interference Ratio (SIR) may be used for further processing and routing, whereas the decoded data with the worse Signal-to-Interference Ratio (SIR) may be discarded.

The outer-loop PC mechanism 41 implemented in the RNC 4 is adapted to generate SIR target adjustment commands to be sent to the first base station (Node B) 2 and the second base station (Node B) 3, respectively. The RNC 4 determines a common SIR target adjustment for both the first base station (Node B) 2 and the second base station (Node B) 3. The SIR target adjustment is based in analogy to the description above on the outer-loop PC mechanism 41 implemented in the RNC 4, which is supplied with the PHY CH quality information value and a target Quality of Service (QoS) value, where in particular the PHY CH quality information value might be the first Cyclic Redundancy Check (CRC_1), the first Frame Error Rate (FER_1) and the like. The algorithm for adjusting the target SIR and/or further target values can be based on the (same) conventionally implemented algorithm such as that illustrated above by the means of pseudo code. The algorithm for adjusting the target SIR and/or further target values can be based on the (same) conventionally implemented algorithm such as that illustrated above by the means of pseudo code.

However, the first base station (Node B) 2 and second base station (Node B) 3 route a first set and a second set of PHY CH quality information to the RNC 4. Due to the fact that a common SIR target adjustment is determined in conjunction with the target QoS value, only one of the both sets of PHY CH quality information is supplied to the outer-loop PC mechanism 41. A physical channel (PHY CH) quality information evaluation mechanism 42, which is supplied with the two sets of PHY CH quality information originating from the first and second base stations (Node B) 2, 3, is implemented in the RNC 4, to obtain a PHY CH quality information value from the sets and to supply the obtained PHY CH quality information value to the outer-loop PC mechanism 41, to enable the determination of the SIR target adjustment.

For instance, the physical channel (PHY CH) quality information evaluation mechanism 42 could be based on a minimum determination. Consequently, the physical channel (PHY CH) quality information value obtained by the physical channel (PHY CH) quality information evaluation mechanism 42 may be one out of the group including:

minimum of the first Cyclic Redundancy Check (CRC_1) of the first set (set 1) of

PHY CH quality information (determined by the first base station) and the first Cyclic Redundancy Check (CRC_1) of the second set (set 2) of PHY CH quality information (determined by the second base station 3); minimum of the first Frame Error Rate (FER_1) of the first set (set 1) and the first Frame Error Rate (FER_1) of the second set(set 2); minimum of the first Bit Error Rate (BER_1) of the first set (set 1) and the first Bit Error Rate (BER_1) of the second set(set 2); minimum of the first received signal energy per bit divided by noise spectral density 1 (Eb/E0_l) of the first set (set 1) and the first received signal energy per bit divided by noise spectral density 1 (Eb/E0_l) of the second set (set 2); and the like.

A command on the basis of the determined SIR target adjustment is then communicated to the first and second base stations (Node B) 2, 3 to adjust the target SIR currently valid for (fast) closed-loop PC mechanisms 23. In accordance with the closed-loop PC mechanism 23 of each of the first and second base stations (Node B) 2,3, the mobile station (UE) 1 receives one or more transmit power control (TPC) commands from the closed-loop PC mechanisms 23, which are generated on the basis of the current SIR in uplink measured by the first base station (Node B) 2 and the target SIR commanded by the RNC 4 as well as the on the basis of the current SIR in uplink measured by the second base station (Node B) 3 and the target SIR commanded by the RNC 4. As aforementioned,

Due to the fact that one base station of the set of base stations (here the first and the second base stations (Node B) 2, 3) receiving a correct uplink signal is sufficient, the mobile station can adjusts its transmission power to the lowest commanded, the corresponding TPC command may originate from either the first base station (Node B) 2 or the second base station (Node B) 3. One or more TPC commands, which command a higher transmission power, can be discarded. Further selection rules may be also applicable. A corresponding TPC validation mechanism may be implemented in the mobile station (UE) 1, enabling the mobile station (UE) 1 for selecting the one or more appropriate TPC commands.

With reference to Figs. 3 and 4, the operation sequence charts are illustrated, which enable outer-loop PC with uplink transmission using ARQ/HARQ error correction according to an embodiment of the present invention. On the basis of the description given above, the skilled reader will appreciate that the present invention relates to the outer-loop PC mechanism, which involves operations of the base station (Node B) and the Radio Network Controller (RNC) 4, which serve currently for data communication with the mobile station (UE). In case of soft handover (SHO), two or more base station may serve for data communication with the mobile station (UE). The outer-loop PC mechanism intervenes in the (fast) closed-loop PC mechanism as a function of the base station (Node B) by commanding a target (SIR) value of the closed-loop PC mechanism. The mobile station (UE) and the base station (Node B) are involved in the (fast) closed-loop PC mechanism; i.e. the base station (Node B) sends TPC commands to the mobile station (UE) for commanding the transmission power thereof, where the TPC commands are generated on the basis of measured radio frequency signal values (SIR) and the target (SIR) value. Consequently, the outer-loop PC mechanism effects only indirectly the transmission power of the mobile station (UE). The (fast) closed-loop PC mechanism and operations are included for the sake of completeness.

Fig. 3 relates to the operation sequence carried out in the system illustrated in Fig. 1 and described with reference thereto in detail.

With reference to the mobile station (UE) 1, the transmission power has a certain power level, which may be set by inner-loop PC mechanism or TPC commands received before. In an operation SlO, the mobile station (UE) 1 transmits an original data packet via the Uu (air) interface to the base station (Node B) 2, which currently serves the mobile station (UE) 1.

With reference to the base station (Node B) 2, the original data packet is received via the Uu (air) interface and decoded in an operation S20. In accordance with the error recovery mechanism for instance on the basis of an ARQ/HARQ mechanism in an operation S21, the base station (Node B) 2 transmits back ACK/NACK signaling to the mobile station (UE) 1.

In case of NACK signaling, the mobile station (UE) 1 retransmits n-th data packets to the base station (Node B) 2 in an operation SI l, which n-th retransmission data packets are combined with the original data packet for error recovery, in the operation S21. In an operation S22, the physical channel (PHY CH) quality information is determined, which reflects the actual channel condition in uplink. For example, the PHY CH quality information can be obtained from the original data packet. In an operation S22, the soft quality information is determined, preferably on the basis of the error corrected or error recovered data packet obtained from the error recovery mechanism. Subsequent in an operation S24, the (error corrected / error recovered) data packet, the soft quality information, and the PHY CH quality information is routed to the RNC 4, which serves the mobile station (UE) 1.

With reference to the Radio Network Controller (RNC) 4, the (error corrected / error recovered) data packet, the soft quality information, and the PHY CH quality information is received in an operation S40. In an operation S41, the SIR target adjustment is determined. In order to obtain a SIR target adjustment, which corresponds to the actual channel condition in uplink, the determination is based on one of the PHY CH quality information values included in the PHY CH quality information. The target Quality of Service value, in relation to which the employed PHY CH quality information value is set, is pre-determined by the RNC 4, preferably on the basis of a decision which quality of service is required, desired, and/or applicable for the service to which the transmitted data packet relates. A SIR target adjustment command is subsequently sent to the base station (Node B) 2.

With reference back to base station (Node B) 2, the SIR target adjustment command is received and the target SIR value of the (fast) closed-loop PC mechanism is adjusted accordingly in an operation S25. In an operation S26, the adjusted target SIR value of the

(fast) closed-loop PC mechanism is now applied for eventuating currently measured SIR in uplink and generating TPC commands addressing the mobile station (UE) 1, to command increasing or decreasing of the transmission power level of the mobile station (UE) 1. The transmission power level is used for transmitting uplink radio frequency signals, i.e. successive data packet to the base station (Node B) 2.

Fig. 4 relates to the operation sequence carried out in the system illustrated in Fig. 1 and described with reference thereto in detail. With reference to the mobile station (UE) 1, the transmission power has a certain power level, which may be set by inner-loop PC mechanism or TPC commands received before. In an operation SlOO, the mobile station (UE) 1 transmits an original data packet via the Uu (air) interface to the base station (Node B) 2 and the base station (Node B) 3, which concurrently serve the mobile station (UE) 1 in soft handover (SHO).

With reference to the first base station (Node B) 2, the original data packet is received via the Uu (air) interface and decoded in an operation S200. In accordance with the error recovery mechanism for instance on the basis of an ARQ/HARQ mechanism, the first base station (Node B) 2 transmits back ACK/NACK signaling to the mobile station (UE) 1. In case of NACK signaling, the mobile station (UE) 1 retransmits n-th data packets to the base station (Node B) 2, which n-th retransmission data packets are combined with the original data packet for error recovery. In an operation S210, the physical channel (PHY CH) quality information is determined, which reflects the actual channel condition in uplink. For example, the PHY CH quality information can be obtained from the original data packet. Moreover, the soft quality information is determined in the operation S220, preferably on the basis of the error corrected or error recovered data packet obtained from the error recovery mechanism. Subsequent in an operation S220, the (error corrected / error recovered) data packet, the soft quality information, and the PHY CH quality information is routed to the RNC 4, which serves the mobile station (UE) 1.

With reference to the second base station (Node B) 3, the original data packet is received via the Uu (air) interface and decoded in an operation S300. In accordance with the error recovery mechanism, for instance on the basis of an ARQ/HARQ mechanism, the base station (Node B) 2 transmits ACK/NACK signaling back to the mobile station (UE) 1. In case of NACK signaling, the mobile station (UE) 1 retransmits n-th data packets to the second base station (Node B) 3, which n-th retransmission data packets are combined with the original data packet for error recovery. In an operation S310, the physical channel (PHY CH) quality information is determined, which reflects the actual channel condition in uplink. For example, the PHY CH quality information can be obtained from the original data packet. Moreover, the soft quality information is determined in the operation S320, preferably on the basis of the error corrected or error recovered data packet obtained from the error recovery mechanism. Subsequent in an operation S320, the (error corrected / error recovered) data packet, the soft quality information, and the PHY CH quality information is routed to the RNC 4, which serves the mobile station (UE) 1.

With reference to the Radio Network Controller (RNC) 4, the (error corrected / error recovered) the first set of data packet, the soft quality information, and the PHY CH quality information is received in an operation S400 from the first base station (Node B) 2. In an operation S410, the second set of data packet, the soft quality information, and the PHY CH quality information is received from the second base station (Node B) 3.

In an operation S420, the data packets from the fist and second base stations (Node B) 2, 3 are combined, preferably in accordance with macro diversity combining mechanisms.

In an operation S430, a PHY CH quality information value is obtained from the fist and second set of physical channel (PHY CH) quality information, which PHY CH quality information value is adequate for the following operation of determining the SIR target adjustment. The selection of the PHY CH quality information value is operable on the basis of the physical channel (PHY CH) quality information validation mechanism.

In an operation S440, the SIR target adjustment is determined. In order to obtain a SIR target adjustment, which corresponds to the actual channel condition in uplink, the determination is based on the selected PHY CH quality information value obtained from PHY CH quality information validation. The target Quality of Service value, in relation to which the employed PHY CH quality information value is set, is pre-determined by the RNC 4, preferably on the basis of a decision which quality of service is required, desired, and/or applicable for the service to which the transmitted data packet relates. Subsequently, a SIR target adjustment command is essentially concurrently sent to the first base station (Node B) 2 and the second base station (Node B) 3. With reference back to second base station (Node B) 3, the SIR target adjustment command is received and the target SIR value of the (fast) closed-loop PC mechanism is adjusted accordingly in an operation S330. In an operation S340, the adjusted target SIR value of the (fast) closed-loop PC mechanism is now applied for eventuating currently measured SIR in uplink and generating TPC commands addressing the mobile station (UE) 1, to command increasing or decreasing of the transmission power level of the mobile station (UE) 1.

With reference back to first base station (Node B) 2, the SIR target adjustment command is received and the target SIR value of the (fast) closed-loop PC mechanism is adjusted accordingly in an operation S230. In an operation S240, the adjusted target SIR value of the (fast) closed-loop PC mechanism is now applied for eventuating currently measured SIR in uplink and generating TPC commands addressing the mobile station (UE) 1, to command increasing or decreasing of the transmission power level of the mobile station (UE) 1.

In an operation SI lO, the mobile station (UE) 1 receiving TPC commands from the first and the second base station (Node B) 2, 3, supplies the received TPC commands to a TPC validation mechanism, to extract the most advantage transmission power level adjustment.

It should be noted that although the need for soft quality information to be routed to the Radio Network Controller (RNC) is not discussed in detail, the soft quality information is required in soft handover for macro data diversity combining. The soft quality information has to be determined by the base station(s) (Node B) and routed to the Radio Network Controller (RNC). The introduced physical channel (PHY CH) quality information is not applicable for macro data diversity combining in soft handover.

Although the embodiments of the present invention have been described and illustrated in detail, it will be evident to those skilled in the art that various modifications and changes may be made without departing from the scope of the invention as set forth in the appended claims.

Claims

1. Method for a base station (2, 3) of enabling outer-loop power control in data packet transmission employing error recovery mechanism (21), in particular a physical layer error recovery mechanism, said method comprising:

- receiving (S20, S21, S200, S300) one or more data packets from a mobile station (1) via an air interface; wherein said error recovery mechanism (21) is applicable to obtain error recovered data packets; characterized by

- determining (S22, S210, S310) physical channel quality information including one or more physical channel quality values reflecting an actual physical condition of a channel, on which said data packets have been transmitted, wherein said physical channel quality information is independent of said quality of said error recovered data packets;

- transmitting (S24, S220, S320) a set of said error recovered data packets and said physical channel quality information to a radio network controller (4);

- receiving a target adjustment command from said radio network controller (4) and

- adjusting a target value operable with a closed-loop power control mechanism in accordance with said target adjustment command.

2. Method according to claim 1, characterized in that said error recovered data packet is obtained by combining an original data packet and one or more retransmit packets in accordance with said error recovery mechanism; wherein said original data packet received with a first transmission and said retransmit packets received with retransmissions subsequent to said first transmission.

3. Method according to claim 2, characterized in that said physical channel quality information is obtainable on the basis of said original data packet.

4. Method according to anyone of the preceding claims, characterized in that said error recovery mechanism (21) is an automatic repeat request mechanism or a hybrid automatic repeat request mechanism.

5. Method according to anyone of the preceding claims, characterized in that said physical channel quality information comprising at least one value out of a group comprising: cyclic redundancy check, received signal energy per bit divided by noise spectral density; frame error rate; bit error rate.

6. Method according to anyone of the preceding claims, comprising:

- determining (S23, S210, S310) soft quality information from said error recovered data packets; characterized in that said set to be transmitted to said radio network controller (4) includes said error recovered data packets, said soft quality information, and said physical channel quality information.

7. Method according to anyone of the preceding claims, characterized in that said soft quality information enables soft handover handling at said radio network controller.

8. Method according to anyone of the preceding claims, characterized in that said base station (2, 3) is operable in a cellular public land mobile network, in particular in a cellular mobile communication network supporting code division multiple access based technology.

9. Method according to anyone of the preceding claims, characterized in that said base station (2, 3) is operable in a wideband code division multiple access system, in particular a universal mobile telecommunication system.

10. Method for a radio network controller (4) of enabling outer-loop power control in data packet transmission employing error recovery mechanism, in particular a physical layer error recovery mechanism, said method being characterized by: - receiving (S40, S400, S410) a first set of at least one or more error recovered data packets and physical channel quality information from a first base station (2) via a data interface; said physical channel quality information of said first set including one or more physical channel quality values reflecting the actual physical condition of a channel, on which said data packets have been originally received by said first base station

(2), wherein said physical channel quality information is independent of said quality of said error recovered data packets;

- an outer-loop power control entity (41), determining (S41, S400) a target adjustment on the basis of one quality value obtained from said physical channel quality information of said first set and a pre-determined target quality of service value; and

- transmitting a target adjustment command on the basis of said target adjustment to said first base station (2, 3) via said data interface to enable adjustment of a target value of a closed-loop power control entity operable with said first base station (2).

11. Method according to claim 10, characterized in that said physical channel quality information comprising at least one value out of a group comprising: cyclic redundancy check, received signal energy per bit divided by noise spectral density; frame error rate; bit error rate.

12. Method according to claim 10 or claim 11, characterized in that said error recovered data packet is obtained on base station side by applying an error recovery mechanism.

13. Method according to anyone of the claims 9 to 11, said method characterized by:

- receiving (S40, S400, S410) a second set of at least one or more error recovered data packets and physical channel quality information from a second base station (3) via said data interface; said physical channel quality information of said second set including one or more physical channel quality values reflecting the actual physical condition of a channel, on which said data packets have been originally received by said second base station (3), wherein said physical channel quality information is independent of a quality of said error recovered data packets; said data packets of said first set and said second set having been received essentially concurrently by said first base station (2) and said second base station (3);

- a physical channel quality evaluation entity (42), determining (S430) said quality value by considering said physical channel quality information included in said first set and said physical channel quality information included in said second set; and

- transmitting said target adjustment command to said second base station (2, 3) via said data interface to enable adjustment of a target value of a closed-loop power control entity operable with said second base station (3).

14. Method according to claim 13, said method characterized by:

- said physical channel quality evaluation entity (42), determining said quality value on the basis of a relationship of one or more physical channel quality values of said physical channel quality information of said first set and one or more physical channel quality values of said physical channel quality information of said second set.

15. Method according to claim 13 or claim 14, characterized in that said relationship is a function of a physical channel quality value included in said physical channel quality information of said first set and physical channel quality value included in said physical channel quality information of said second set; in particular said function is a minimum function.

16. Method according to anyone of the claims 10 to 15, characterized in that said first set and/or said second set include soft quality information, which represents a quality of said error recovered data packets, wherein said soft quality information enables soft handover handling at said radio network controller (4).

17. Method according to anyone of the claims 10 to 16, characterized in that said radio network controller (4) is operable in a cellular public land mobile network, in particular in a cellular mobile communication network supporting code division multiple access based technology.

18. Method according to anyone of the claims 10 to 17, characterized in that said radio network controller (4) is operable in a wideband code division multiple access system, in particular a universal mobile telecommunication system.

19. Computer program product comprising program code sections for carrying out the steps of anyone of claims 1 to 18, when said program is run on a controller, processor-based device, a computer, a microprocessor based device, a terminal, a network device, a mobile terminal or a mobile communication enabled terminal.

20. Computer program product, comprising program code sections stored on a machine- readable medium for carrying out the steps of anyone of claims 1 to 18, when said program product is run on a controller, processor-based device, a computer, a microprocessor based device, a terminal, a network device, a mobile terminal, or a mobile communication enabled terminal.

21. Computer data signal embodied in a carrier wave and representing instructions, which when executed by a processor cause the steps of anyone of claims 1 to 18 to be carried out.

22. Base station device (2, 3) enabling outer-loop power control in data packet transmission employing error recovery mechanism, in particular a physical layer error recovery mechanism, said device comprising: - an air interface (Uu) adapted to receive (S20, S21, S200, S300) one or more data packets from a mobile station (1), - said error recovery mechanism (21) applicable to obtain error recovered data packets from said received data packets;

- a physical channel quality detection entity (22) adapted to determining (S22, S210, S310) physical channel quality information including one or more physical channel quality values reflecting the actual physical condition of a channel, on which said data packets are received, wherein said physical channel quality information is independent of a quality of said error recovered data packets;

- a data interface (Iub) adapted to transmit (S24, S220, S320) a set of said error recovered data packets and said physical channel quality information to a radio network controller device (4); and to receive a target adjustment command from said radio network controller device (4); and

- a closed-loop power control mechanism (23) adapted to receive said target adjustment command and to adjust a target value in accordance with said target adjustment command.

23. Device according to claim 22, characterized by

- a channel decoder entity (20) adapted to determine (S23, S210, S310) soft quality information from said error recovered data packets, wherein soft quality information represents a quality of said error recovered data packets, wherein said soft quality information enables soft handover handling at said radio network controller device

(4); wherein said set to be transmitted to said radio network controller device includes said error recovered data packets, said soft quality information, and said physical channel quality information.

24. Device according to claim 22 or claim 23, characterized in that said base station device (2, 3) is operable in a cellular public land mobile network, in particular in a cellular mobile communication network supporting code division multiple access based technology, more particularly in a wideband code division multiple access system, in particular a universal mobile telecommunication system.

25. Radio network controller device (4) enabling outer-loop power control in data packet transmission employing error recovery mechanism, in particular a physical layer error recovery mechanism; said device characterized by - a data interface (Iub) adapted to receive (S40, S400, S410) a first set of at least one or more error recovered data packets and physical channel quality information from a first base station device (2); said physical channel quality information of said first set including one or more physical channel quality values reflecting the actual physical condition of a channel, on which said data packets have been originally received by said first base station device (2), wherein said physical channel quality information is independent of a quality of said error recovered data packets;

- an outer-loop power control entity (41) adapted to determine (S41, S400) a target adjustment on the basis of one quality value obtained from said physical channel quality information of said first set and a pre-determined target quality of service value; and

- said data interface (Iub) adapted to transmit a target adjustment command on the basis of said target adjustment to said first base station device (2, 3) to enable adjustment of a target value of a closed-loop power control mechanism (23) operable with said first base station device (2, 3).

26. Device according to claim 25, said device characterized by:

- said data interface (Iub) adapted to receive (S40, S400, S410) a second set of at least one or more error recovered data packets and physical channel quality information from a second base station device (3); said physical channel quality information of said second set including one or more physical channel quality values reflecting the actual physical condition of a channel, on which said data packets have been originally received by said second base station device (3), wherein said physical channel quality information is independent of a quality of said error recovered data packets; said data packets of said first set and said second set having been received essentially concurrently by said first base station device (2) and said second base station device

(3);

- said physical channel quality evaluation entity (42) adapted to determine (S430) said quality value by considering said physical channel quality information included in said first set and said physical channel quality information included in said second set; and

- said data interface (Iub) adapted to transmit said target adjustment command to said second base station device (2, 3) to enable adjustment of a target value of a closed- loop power control mechanism (23) operable with said second base station device

(3).

27. Device according to claim 25 or claim 26, said device characterized in that said first set and/or said second set include said at least one or more error recovered data packets, soft quality information, and said physical channel quality information, which represents a quality of said error recovered data packets, wherein said soft quality information enables soft handover handled at said radio network controller device (4).

28. Device according to anyone of the claims 25 to 27, characterized in that said radio network controller device (4) is operable in a cellular public land mobile network, in particular in a cellular mobile communication network supporting code division multiple access based technology, more particularly in a wideband code division multiple access system, in particular a universal mobile telecommunication system.

29. System including at least a first base station device (2) and a radio access network controller device (4) being part of a radio network subsystem, which enables outer-loop power control in data packet transmission employing error recovery mechanism, in particular a physical layer error recovery mechanism; said system comprising: - said first base station device (2), an air interface (Uu) adapted to receive (S20, S21,

S200, S300) one or more data packets from a mobile station (1), - said first base station device (2), said error recovery mechanism (21) applicable to obtain error recovered data packets from said received data packets;

- said first base station device (2), a physical channel quality detection entity (22) adapted to determining (S22, S210, S310) physical channel quality information including one or more physical channel quality values reflecting the actual physical condition of a channel, on which said data packets are received, wherein said physical channel quality information is independent of a quality of said error recovered data packets;

- said first base station device (2), a data interface (Iub) adapted to transmit (S24, S220, S320) a first set of said error recovered data packets and said physical channel quality information to a radio network controller device (4);

- said radio network controller device (4), a data interface (Iub) adapted to receive (S40, S400, S410) a first set from said first base station device (2);

- said radio network controller device (4), an outer-loop power control entity (41) adapted to determine (S41, S400) a target adjustment on the basis of one quality value obtained from said physical channel quality information of said first set and a pre-determined target quality of service value;

- said radio network controller device (4), said data interface (Iub) adapted to transmit a target adjustment command on the basis of said target adjustment to said first base station device (2);

- said first base station device (2), said data interface adapted to receive said target adjustment command from said radio network controller device (4); and

- said first base station device (2), a closed-loop power control mechanism (23) adapted to receive said target adjustment command and to adjust a target value in accordance with said target adjustment command.

30. System according to claim 29, comprising a second base station device, said system comprising:

- said second base station device (3), an air interface (Uu) adapted to receive (S20, S21, S200, S300) one or more data packets from a mobile station (1), - said second base station device (3), said error recovery mechanism (21) applicable to obtain error recovered data packets from said received data packets;

- said second base station device (3), a physical channel quality detection entity (22) adapted to determining (S22, S210, S310) physical channel quality information including one or more physical channel quality values reflecting the actual physical condition of a channel, on which said data packets are received, wherein said physical channel quality information is independent of a quality of said error recovered data packets;

- said second base station device (3), a data interface (lub) adapted to transmit (S24, S220, S320) a second set of said error recovered data packets and said physical channel quality information to a radio network controller device (4);

- said radio network controller device (4), a data interface (lub) adapted to receive (S40, S400, S410) said second set from said second base station device (3); said data packets of said first set and said second set having been received essentially concurrently by said first base station device (2) and said second base station device

(3);

- said radio network controller device (4), a physical channel quality evaluation entity (42) adapted to determine (S430) said quality value by considering said physical channel quality information included in said first set and said physical channel quality information included in said second set;

- said radio network controller device (4), said data interface (lub) adapted to transmit a target adjustment command on the basis of said target adjustment to said second base station device (3);

- said second base station device (3), said data interface (lub) adapted to receive said target adjustment command from said radio network controller device (4); and

- said second base station device (3), a closed-loop power control mechanism (23) adapted to receive said target adjustment command and to adjust a target value in accordance with said target adjustment command.

31. System according to claim 29 or claim 30, comprising: - said first base station device (2) and/or said second device (3), a channel decoder entity (20) adapted to determine (S23, S210, S310) soft quality information from said error recovered data packets; wherein said first and/or said second set to be transmitted to said radio network controller device (4) include additionally said quality information, which enables soft handover handling at said radio network controller device (4).

32. System according to anyone of the claims 29 to 31 , wherein the first and/or second base station device (2, 3) is a base station device according to anyone of the claims 22 to 24; and/or wherein the radio network controller device (4) is a radio network controller device according to anyone of the claims 25 to 28.