WO2016188573A1 - Methods and nodes in a wireless communication network - Google Patents

Abstract

A Controlling Network Node (130) and a method (500) therein, in a communication network (100), for providing a power control command for a RL (140-1, 140-2, …, 140-n) associated with a UE (120). The CNN (130) comprises a processing unit (820), configured to dedicate one set of power control bits (510-9) comprised in a DL dedicated physical channel slot (300), for RLs (140-1, 140-2, …, 140-n) communicating with any non-serving cell (320); set the dedicated set of power control bits (510-9) to an incrementing command; detect a RL (140- 1, 140-2, …, 140-n) for communication with any non-serving cell (320); assign the dedicated set of power control bits (510-9) to the detected RL (140-1, 140-2, …, 140-n); and provide the DL dedicated physical channel slot (300) to the UE (120).

Description

METHODS AND NODES IN A WIRELESS COMMUNICATION NETWORK

TECHNICAL FIELD

Implementations described herein generally relate to a controlling network node, a method therein, a User Equipment (UE) and a system. In particular, a mechanism is herein de- scribed, for providing a power control command for at least one Radio Link (RL) associated with a UE.

BACKGROUND

The explosion of data requirements in today^'s cellular networks impose a heavy burden in terms of bandwidth requirements both in Downlink (DL) and Uplink (UL). In the present context, the expression DL is used for the transmission path from the base station to a UE. The expression UL is used for the transmission path in the opposite direction i.e. from the UE to the base station. The Universal Mobile Telecommunications System (UMTS) network, given its near ubiquitous presence, is in particular need of features which improve the spectral efficiency of the network. Due to the long time UMTS has existed in the market, it is especially difficult to find cost-effective solutions to achieve performance improvements in both or either UL and DL. The most advanced features currently available often require the adoption of new and more expensive architectures or the installation of more capable hardware.

From an efficiency view point, it is desirable to introduce new mechanisms for improving efficiency of communication networks.

SUMMARY

It is therefore an object to obviate at least some of the above mentioned disadvantages and improve the communication in a wireless communication network. This and other objects are achieved by the features of the appended independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures.

According to a first aspect, a Controlling Network Node (CNN) is provided in a communica- tion network, for providing a power control command for at least one Radio Link (RL) associated with a User Equipment (UE). The CNN comprises a processing unit, configured to dedicate one set of power control bits comprised in a DL dedicated physical channel slot, for RLs communicating with any non-serving cell. Further, the processing unit is also configured to set the dedicated set of power control bits to an incrementing power control command. The processing unit is in addition configured to detect at least one RL on which the UE is communicating with any non-serving cell. Also, the processing unit is configured to assign the dedicated set of power control bits to the detected at least one RL on which the UE is communicating with any non-serving cell. Further the processing unit is also configured to provide the DL dedicated physical channel slot to the UE. Thanks to the dedicated set of power control bits assigned to any RL on which the UE is communicating with any non-serving cell, a plurality of superfluous power control commands could be transmitted in one single dedicated set of power control bits. The power control commands from non-serving cells are not superfluous per se, but they become redundant by using the same set of power control bits ("1 1 ") for all non-serving RLs between a plurality of UEs and one given cell (above a certain load threshold). The set of power control bits ("1 1 ") is "dedicated" in the sense that it is the set of bits corresponding to a specific chip- offset, but it is also "shared" in the sense that that same power control UP is shared by all the non-serving RLs belonging to the same cell. This gives the opportunity to save DL signalling overhead in a soft/ softer handover scenario. Thereby DL control signalling overhead is reduced in a soft handover/ softer handover scenario. Thus the communication within the wireless communication network is improved.

In a first possible implementation of the CNN according to the first aspect, the processing unit is further configured to detect that the UE is wirelessly communicating with a serving cell and at least one non-serving cell of at least one network node in the communication network.

Thereby a UE in a (potential) handover, or soft handover situation may be detected and appropriate measures for a providing power control commands may be taken. In a second possible implementation of the CNN according to the first aspect, or the first possible implementation of the first aspect, the processing unit is further configured to determine when at least one cell in the communication network has a load exceeding a threshold limit. The processing unit is also configured to provide the DL dedicated physical channel slot to the UE when at least one cell has a load exceeding the threshold limit. The "DL dedicated physical channel slot" may be the specific set of power control bits, carried by the e-FDPCH and shared by all the non-serving RLs of a given cell, above a load threshold. By providing the DL dedicated physical channel slot to the UE only when at least one cell has a load exceeding the threshold limit, the method is only performed when it is re- quired. Thereby processing power and energy are saved.

In a third possible implementation of the CNN according to the first aspect, or any of the previous possible implementations of the first aspect, the processing unit may be further configured to assign the dedicated set of power control commands to the detected at least one RL on which the UE is communicating with any non-serving cell, only when the UE is capable of utilising different sets of power control commands for different RLs comprised in an active set of RLs.

Thereby, it is assured that the UE is compatible with disclosed method of providing a com- mon power control command to a plurality of RLs.

In a fourth possible implementation of the CNN according to the first aspect, or any of the previous possible implementations of the first aspect, the processing unit may be further configured to detect when a difference between the estimated UL Signal-to-lnterference Ra- tio (SIR) as perceived by the non-serving cell and the estimated UL SIR as perceived by the serving cell exceeds a threshold value. Also, the processing unit may be configured to instruct the UE to decrease the transmission signal strength, based on the estimated uplink SIR as perceived by the non-serving cell, via a transmission power command transmitted by the serving cell.

Thereby, by reducing the transmission power of the UE, in comparison with letting the serving cell control the transmission power of the UE, energy is saved by the UE. Thereby the time between battery re-charge of the UE is prolonged, which provides a longer operational time for the user of the UE. Also UL interference is reduced, as the transmission power of the UE is reduced, leading to an enhanced user experience of other UE users.

In a fifth possible implementation of the CNN according to the first aspect, or any of the previous possible implementations of the first aspect, the processing unit is configured to instruct the UE to decrease the transmission signal strength by setting an offset value, based on the detected difference between the estimated UL SIR as perceived by the non-serving cell and the estimated UL SIR as perceived by the serving cell. Thereby, problems associated with imbalance between UL and DL may be omitted or at least reduced, leading to a further improved communication network.

In a sixth possible implementation of the CNN according to the first aspect, or any of the previous possible implementations of the first aspect, the processing unit is further configured to adjust the offset value until the difference in number of power control down commands from the non-serving cell and the serving cell over a reference period is smaller than a threshold level. Thereby the power control commands may be transmitted from a non-serving cell to the UE, although the inner loop power control of the serving cell is considerably much faster than the transmission time over the backbone network from the non-serving cell to the serving cell via the CNN. In a seventh possible implementation of the CNN according to the first aspect, or any of the previous possible implementations of the first aspect, the processing unit is configured to permit the UE to increase the number of RLs in an active set of RLs, compared to an initial number of RLs, by: controlling the number of RLs in the active set; and/ or increasing a 1 A threshold value, with respect to a serving cell RL strength, for transmitting a 1 A report from the UE to the CNN; and/ or increasing a 1 B threshold value, with respect to a serving cell RL strength, for transmitting a 1 B report from the UE to the CNN.

Thus, the UL capacity may be increased by increasing the UL active set size without increasing the control overhead in DL thus without penalising the DL capacity. Thereby the commu- nication within the wireless communication network is improved.

In an eighth possible implementation of the CNN according to the first aspect, or any of the previous possible implementations of the first aspect, the CNN is distinct from the at least one network node in the communication network. Also, the communication network is a Uni- versal Mobile Telecommunications System (UMTS) network. The CNN is a Radio Network Controller (RNC) and the at least one network node is a Node B.

Thereby, a convenient and operationally reliable implementation form of the first aspect is enabled.

In an ninth possible implementation of the CNN according to the first aspect, or any of the previous possible implementations of the first aspect, the DL dedicated physical channel is an enhanced Fractional Dedicated Physical Channel (e-FDPCH) as defined by the 3GPP Release 7 or later of the specification of UMTS.

Thus an alternative implementation form is enabled.

In a tenth possible implementation of the CNN according to the first aspect, or any of the previous possible implementations of the first aspect, the CNN is comprised in the at least one network node in the communication network. Thereby, yet an alternative implementation form is enabled.

In an eleventh possible implementation of the CNN according to the first aspect, or any of the previous possible implementations of the first aspect, the CNN is configured to provide power control command for RLs associated with a plurality of UEs, communicating with any non-serving cell, by assigning the dedicated set of power control bits to the RLs on which the plurality of UEs are communicating with any non-serving cell.

Thereby DL capacity is saved in the network. According to a second aspect, a method is provided for use in a CNN in a communication network. The method aims at providing a power control command for at least one RL associated with a UE. The method comprises dedicating one set of power control bits comprised in a DL dedicated physical channel slot, to RLs communicating with any non-serving cell. In addition the method comprises setting the dedicated set of power control bits to an incre- menting power control command. Furthermore, the method also comprises detecting at least one RL on which the UE is communicating with any non-serving cell. The method also comprises assigning the dedicated set of power control bits to the detected at least one RL on which the UE is communicating with any non-serving cell. Also, the method comprises providing the DL dedicated physical channel slot to the UE.

Thanks to the dedicated set of power control bits assigned to any RL on which the UE is communicating with any non-serving cell, a plurality of transmission power control commands could be transmitted in one single dedicated set of power control commands and therefore be made redundant. This is based on the assumption that the serving cell is the cell which usually has the best RL toward the UE and is therefore the one sending power control DOWN commands. Thereby DL control signalling overhead is reduced in a soft handover/ softer handover scenario. Thus the communication within the wireless communication network is improved. In a first possible implementation of the method according to the second aspect, the method comprises detecting that the UE is wirelessly communicating with a serving cell and at least one non-serving cell of at least one network node in the communication network.

Thereby a UE in a (potential) handover, or soft handover situation may be detected and appropriate measures for a providing power control commands may be taken.

In a second possible implementation of the method according to the second aspect, or the first possible implementation of the second aspect, the method further comprises determining a cell load exceeding a threshold limit for the cell in the communication network. Further the method comprises providing the downlink dedicated physical channel slot to the UE in the cell has a load exceeding the threshold limit.

By providing the DL dedicated physical channel slot to the UE only when at least one cell has a load exceeding the threshold limit, the method is only performed when it is required, i.e. when at least one cell has a load exceeding a threshold limit. Thereby processing power and energy are saved. Moreover, activating the feature only when it is needed by the DL capacity requirements, preserves the possibility, also for the non-serving cell, to control the UE in cases of UL/ DL imbalance. In a third possible implementation of the method according to the second aspect, or any of the previous possible implementations of the second aspect, the method further comprises assigning the dedicated set of power control commands to the detected RL on which the UE is communicating with any non-serving cell, only when the UE is capable of utilising different sets of power control commands for different RLs comprised in an active set of RLs.

Thereby, it is assured that the UE is compatible with disclosed method of providing a common power control command to a plurality of RLs.

In a fourth possible implementation of the method according to the second aspect, or any of the previous possible implementations of the second aspect, the method further comprises detecting when a difference between the estimated UL SIR as perceived by the non-serving cell and the estimated UL SIR as perceived by the serving cell exceeds a threshold value. In addition the method comprises instructing the UE to decrease the transmission signal strength/ quality, based on the estimated UL SIR as perceived by the non-serving cell, via a transmission power command transmitted by the serving cell. Thereby, by reducing the transmission power of the UE, in comparison with letting the serving cell control the transmission power of the UE, energy is saved by the UE. Thereby the time between battery re-charge of the UE is prolonged, which provides a longer operational time for the user of the UE. Also UL interference is reduced, as the transmission power of the UE is reduced, leading to an enhanced user experience of other UE users.

In a fifth possible implementation of the method according to the second aspect, or any of the previous possible implementations of the second aspect, the instruction to decrease the transmission signal strength of the UE comprises an offset value, based on the detected difference between the estimated UL SIR as perceived by the non-serving cell and the esti- mated UL SIR as perceived by the serving cell.

Thereby, problems associated with imbalance between UL and DL may be at least reduced, leading to a further improved communication network. In a sixth possible implementation of the method according to the second aspect, or any of the previous possible implementations of the second aspect the offset value is adjusted until the difference in number of power control down commands from the non-serving cell and the serving cell over a reference period is smaller than a threshold level. Thereby the power control commands may be transmitted from a non-serving cell to the UE, although the inner loop power control of the serving cell is considerably much faster than the transmission time over the backbone network from the non-serving cell to the serving cell via the CNN. In a seventh possible implementation of the method according to the second aspect, or any of the previous possible implementations of the second aspect, the UE is permitted to increase the number of RLs in an active set of RLs, by: controlling the number of RLs in the active set; and/ or increasing a 1 A threshold value, with respect to a serving cell RL strength, for transmitting a 1 A report from the UE to the CNN; and/ or increasing a 1 B threshold value, with respect to a serving cell RL strength, for transmitting a 1 B report from the UE to the CNN. Thus, the UL capacity may be increased by increasing the UL active set size without increasing the control overhead in DL thus without penalising the DL capacity. Thereby the communication within the wireless communication network is improved. In an eighth possible implementation of the method according to the second aspect, or any of the previous possible implementations of the second aspect, the CNN may be distinct from the at least one network node in the communication network. Further the communication network may be a UMTS network. The CNN may be a RNC and the at least one network node may be a Node B.

Thereby, a convenient and operationally reliable implementation form of the first aspect is enabled.

In an ninth possible implementation of the method according to the second aspect, or any of the previous possible implementations of the second aspect, the DL dedicated physical channel may be an e-FDPCH, as defined by the 3GPP Release 7 or later of the specification of UMTS.

Thus an alternative implementation form is enabled.

In a tenth possible implementation of the method according to the second aspect, or any of the previous possible implementations of the second aspect, the CNN may be comprised in the at least one network node in the communication network. Thereby, yet an alternative implementation form is enabled.

In an eleventh possible implementation of the method according to the second aspect, or any of the previous possible implementations of the second aspect, wherein the CNN is configured to provide power control command for RLs associated with a plurality of UEs, communicating with any non-serving cell, by assigning the dedicated set of power control commands to the RLs on which the plurality of UEs are communicating with any non-serving cell.

Thereby DL capacity is saved in the network. According to a third aspect, a computer program is provided, comprising a program code for performing a method according to the second aspect, or any of the previous possible implementations of the second aspect, when the computer program runs on a computer. Thanks to the dedicated set of power control bits assigned to any RL on which the UE is communicating with any non-serving cell, a plurality of superfluous power control commands could be transmitted in one single dedicated set of power control bits. The power control commands from non-serving cells are not superfluous per se, but they become redundant by using the same set of power control bits ("1 1 ") for all non-serving RLs between a plurality of UEs and one given cell (above a certain load threshold). The set of power control bits ("1 1 ") is "dedicated" in the sense that it is the set of bits corresponding to a specific chip- offset, but it is also "shared" in the sense that that same power control UP is shared by all the non-serving RLs belonging to the same cell. This gives the opportunity to save DL signalling overhead in a soft/ softer handover scenario. Thereby DL control signalling overhead is reduced in a soft handover/ softer handover scenario. Thus the communication within the wireless communication network is improved.

According to a fourth aspect, a UE is provided in a communication network, for wireless communication with a serving cell and at least one non-serving cell of at least one network node in the communication network. Further the UE is assigned a downlink dedicated physical channel slot from the CNN according to the first aspect, or any possible implementation thereof.

According to a fifth aspect, a system is provided in a communication network, for providing a power control command for at least one RL associated with a UE. The UE is configured for wireless communication with a serving cell and at least one non-serving cell of at least one network node in the communication network. The system comprises a CNN according to the first aspect, or any possible implementation thereof, and a UE according to the fourth aspect.

The advantages of the UE according to the third aspect or the system according to the fourth aspect are the same as those for the corresponding CNN according to the first aspect, method according to the second aspect and computer program according to the third aspect. Other objects, advantages and novel features of the described aspects will become apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are described in more detail with reference to attached drawings, illustrating examples in which:

Figure 1 is a block diagram illustrating wireless communication according to some em- bodiments.

Figure 2A is a block diagram illustrating a radio frame for wireless communication according to some embodiments.

Figure 2B is a block diagram illustrating a radio frame for wireless communication according to some embodiments.

Figure 3 is a block diagram illustrating wireless communication according to some embodiments.

Figure 4 is a flow chart illustrating a method according to an embodiment.

Figure 5 is a block diagram illustrating an enhanced FDPCH slot.

Figure 6A is a block diagram illustrating depicting received DL signal strength of RLs and the modification of an active set of RLs for the UE according to some embodiments.

Figure 6B is a block diagram illustrating depicting received DL signal strength of RLs and the modification of an active set of RLs for the UE according to some embodiments, in an UL congestion situation.

Figure 7 is a flow chart illustrating a method according to an embodiment.

Figure 8 is a block diagram illustrating wireless communication according to some embodiments.

DETAILED DESCRIPTION

Embodiments of the invention described herein are defined as nodes and methods therein, which may be put into practice in the embodiments described below. These embodiments may, however, be exemplified and realised in many different forms and are not to be limited to the examples set forth herein; rather, these illustrative examples of embodiments are provided so that this disclosure will be thorough and complete. Still other objects and features may become apparent from the following detailed description, considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the herein disclosed embodiments, for which reference is to be made to the appended claims. Further, the drawings are not necessarily drawn to scale and, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. Figure 1 is a schematic illustration over a wireless communication network 100 comprising a plurality of network nodes 110-1 , 110-2, 110-3, which are controlled by a Controlling Network Node (CNN) 130. Any, some or all of the network nodes 1 10-1 , 1 10-2, 1 10-3 may communicate wirelessly with a UE 120 over a Radio Link (RL) 140-1 , 140-2, 140-n, where n is an arbitrary integer in the interval 0 < n <∞.

The wireless communication network 100 may at least partly be based on radio access technologies such as, e.g., 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE), LTE-Advanced, Evolved Universal Terrestrial Radio Access Network (E-UTRAN), Universal Mobile Telecommunications System (UMTS), Global System for Mobile Commu- nications (originally: Groupe Special Mobile) (GSM)/ Enhanced Data rate for GSM Evolution (GSM/EDGE), Wideband Code Division Multiple Access (WCDMA), Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, Single-Carrier FDMA (SC-FDMA) networks, Worldwide Interoperability for Microwave Access (WiMax), or Ultra Mobile Broadband (UMB), High Speed Packet Access (HSPA) Evolved Universal Terrestrial Radio Access (E-UTRA), High-Speed Uplink Packet Access (HSUPA), High Speed Downlink Packet Access (HSDPA), Universal Terrestrial Radio Access (UTRA), GSM EDGE Radio Access Network (GERAN), 3GPP2 CDMA technologies, e.g., CDMA2000 1 x RTT and High Rate Packet Data (HRPD), Wi-Fi, or similar, just to mention some few options. The expressions "wireless communication net- work", "wireless communication system" and/ or "cellular telecommunication system" may within the technological context of this disclosure sometimes be utilised interchangeably.

However, subsequently the wireless communication network 100 will be described as an UMTS system wherein the CNN 130 is a Radio Network Controller (RNC) and the network node 1 10-1 , 1 10-2, 1 10-3 is a Node B, or NB.

In the illustrated embodiment, the network nodes 1 10-1 , 1 10-2, 1 10-3 are represented by a radio network node or base station, such as e.g., a Radio Base Station (RBS) or Base Transceiver Station (BTS), which in some networks may be referred to as eNB, NodeB, NB or B- node, Access Point, pico base station, femto base station, beacon device, relay node, repeater or any other network node configured for communication with the UE 120 over a wireless interface, depending, e.g., of the radio access technology and/ or terminology used. The UE 120 may in this illustrated embodiment be represented by a mobile station also known as a mobile device, wireless terminal, mobile telephone, cellular telephone, computer tablet or laptop with wireless capability, etc.

5

The UE 120 in the present context may be, for example, portable, pocket-storable, handheld, computer comprised, or vehicle-mounted mobile devices, enabled to communicate voice and/ or data, via the network nodes 1 10-1 , 1 10-2, 1 10-3 and the wireless communication network 100.

10

The wireless communication network 100 may cover a geographical area which is divided into cell areas, with each cell area being served by a network node, such as the illustrated network nodes 1 10-1 , 1 10-2, 1 10-3.

15 Sometimes, the expression "cell" may be used for denoting the network node itself. However, the cell may also in normal terminology be used for the geographical area where radio coverage is provided by the network node at a base station site. Any of the network nodes 1 10-1 , 1 10-2, 1 10-3, situated on the base station site, may serve one or several cells. The network nodes 1 10-1 , 1 10-2, 1 10-3 may communicate over the air interface operating on

20 radio frequencies with any mobile device 120 within range of the network nodes 1 10-1 , 1 10- 2, 1 10-3. The communication between each cell and the UE 120 is made over a RL 140-1 , 140-2, 140-n.

It is to be noted that the illustrated network setting of three instances of the network nodes 25 1 10-1 , 1 10-2, 1 10-3 and one UE 120 in Figure 1 is to be regarded as a non-limiting example of an embodiment only. The wireless communication network 100 may comprise any other number and/ or combination of the discussed network nodes 1 10-1 , 1 10-2, 1 10-3 and/ or UE 120. A plurality of UEs 120 and another configuration of network nodes 1 10-1 , 1 10-2, 1 10-3 may thus be involved in some embodiments of the disclosed invention.

30

Thus whenever "one" or "a" network nodes 1 10-1 , 1 10-2, 1 10-3 and/ or UE 120 is referred to in the present context, a plurality of the network nodes 1 10-1 , 1 10-2, 1 10-3, and/ or UE 120 may be involved, according to some embodiments. The purpose of the illustration in Figure 1 is to provide a simplified, general overview of the wireless communication network 100 and the involved methods and nodes, such as the network nodes 1 10-1 , 1 10-2, 1 10-3, the UE 120, the CNN 130 as herein described, and the functionalities involved.

5

In relation to some of the disclosed embodiments, the relevant aspects of the UMTS architecture are the concepts of Soft Handover (SHO) and Softer HandOver (SoHO). The term handover, or handoff as it also may be referred to as, refers to the process of transferring an ongoing call or data session from one RL 140-1 , 140-2, 140-n connected to the commu- 10 nication network 100, to another RL 140-1 , 140-2, 140-n.

A UE 120 can have an active connection to more than one cell. The set of cells which have an active connection to the UE 120 and are able to decode the signal received from the UE 120 form the active set of the UE 120. In case the cells belong to the same network node

15 1 10-1 , 1 10-2, 1 10-3, the received signal is soft combined and may be referred to as Softer HandOver (SoHO). If the cells belong to different network nodes 1 10-1 , 1 10-2, 1 10-3, the frames may be combined after decoding (e.g. via Selection Combining) and may be referred to as Soft Handover (SHO). A new RL 140-1 , 140-2, 140-n may be added to the active set or removed from it, based on event-based measurement reports generated by the UE

20 120. Such measurement reports are called respectively the 1 A and 1 B events reports.

Starting from 3GPP Release 6 of UMTS, there are four types of DL dedicated physical channels, the Downlink Dedicated Physical Channel (DL DPCH), the Fractional Dedicated Physical Channel (F-DPCH), the Enhanced Dedicated Channel (E-DCH) Relative Grant Channel 25 (E-RGCH), and the E-DCH Hybrid Automatic Repeat re-Quest (ARQ) Indicator Channel (E- HICH). In the herein described embodiments, the DPCH and the DL DPCH are primarily discussed.

The DL DPCH is a dedicated (per UE) channel which carries the DL Dedicated Physical 30 Control Channel (DPCCH) and the DL Dedicated Physical Data Channel (DPDCH). The DL DPCCH, which carries control information, uses significant power which is therefore not available for data.

The DL F-DPCH, introduced in 3GPP Release 6 of UMTS, is a dedicated channel which 35 saves the codes needed for power control by carrying the power control command for up to 10 UEs onto a single SF256 code. The active set in UL is the set of cells which have an active connection to the UE 120 and are able to decode the signal received from the UE 120. In case the cells belong to the same network node 1 10-1 , 1 10-2, 1 10-3, the received signal is soft combined and may be referred to as Softer Handover (SoHO). If the cells belong to different network nodes 1 10-1 , 1 10-2, 5 1 10-3, then the frames are combined after decoding (via Selection Combining) and may be referred to as Soft Handover (SHO). A new RL 140-1 , 140-2, 140-n is added to the active set when its DL strength such as e.g. Received Signal Code Power (RSCP) is within a threshold level such as e.g. 3 dB, for example, from the DL strength of the service cell. One possible shortcoming of this approach is that, being DL and UL path losses from a given UE 120 to a0 given cell not balanced because HSPA uses Frequency Division Duplex (FDD), UL RLs 140- 1 , 140-2, 140-n with the lowest losses may not be identified by the DL RSCP measurement and therefore may not be added to the active set. In FDD, signals are transmitted in different frequency bands in UL and DL. These signals are therefore affected differently by interference etc., in UL and DL respectively.

5

The active set size may typically be limited to 3 RLs 140-1 , 140-2, ... , 140-n in conventional solutions, in order to avoid excessive consumption of DL control information. The consequence of this approach is that useful power in the UL is not demodulated, thus requiring higher UE transmission power which creates greater inter-cell interference. Also, high UE0 transmission power will shorten the battery life time between recharge, thus affecting the user experience.

Within one DL DPCH, dedicated data, generated at Layer 2 and above, are transmitted time- multiplexed with control information, such as e.g. pilot, Transport Format Combination Indi-5 cator (TFCI) and Transmit Power Control (TPC), generated at Layer 1 . The DL DPCH can thus be seen as a time multiplex of a DPDCH and a DPCCH, as shown in Figure 2A, which illustrates a frame structure for DL DPCH.

The 10 ms radio frame 210 is split into 15 slots 220-0, 220-1 , ..., 220-14, each with a duration0 of 2560 chips. The number of bits carried per slot 220-0, 220-1 , 220-14 depends on the Spreading Factor (SF) which varies from 512 for 10 carried bits i.e., 5 Quadrature Phase Shift Keying (QPSK) symbols to 4 for 1280 carried bits (i.e., 640 QPSK symbols).

Starting from 3GPP Release 5 of UMTS, the DPDCH and DPCCH (that compose the DPCH)5 carry respectively layer 3 and layer 1 control information. The SF of the DPCH is typically set to 256. User-plane data are carried on the High Speed Downlink Packet Access (HSDPA) channel. In a typical DPCH configuration, the DPCH channel may consume about 0.5% of the total network node power per RL 140-1 , 140-2, 140-n.

The NTPC bits carried per slot in the DPCCH channel are specified in Table 1 1 of TS 25.21 1 , while the bit pattern and corresponding power control command are shown in Table 1. The Transmitter Power Control (TPC) command 1 typically means that the UE 120 is to increase the UL transmission power while TPC command 0 means that the UE 120 is to decrease the UL transmission power.

Table 1

Starting from 3GPP Release 6 of UMTS, F-DPCH is introduced. Thereby, RLs 140-1 , 140- 2, 140-n belonging to the same active set need to use the same FDPCH offset, expressed as number of chips. Starting from 3GPP Release 7 of UMTS, it has been introduced En- hanced F-DPCH, wherein the RLs 140-1 , 140-2, 140-n belonging to the same active set can use different FDPCH offsets, expressed as number of chips, as a mean of controlling the UL transmission power of the UE 120.

The chip offset may be used as offset for the DL DPCH relative to the PCCPCH timing. The chip offset parameter has a resolution of 1 chip and a range of 0 to 38399 (< 10 ms).

The chip offset parameter may be calculated by the CNN 130 and may be provided to the network node 1 10-1 , 1 10-2, 1 10-3. UEs 120 which are in SHO or SoHO have two or more RLs 140-1 , 140-2, 140-n in the active set. Each RL 140-1 , 140-2, 140-n is power-controlled using the FDPCH. The power-control bits sent in DL are the same in case of RLs 140-1 , 140-2, 140-n belonging to the same Radio Link Set (RLS), that is, to the same network node 1 10-1 , 1 10-2, 1 10-3, but can potentially be different in case of RLs 140-1 , 140-2, 140-n belonging to different RLSs, or network nodes 1 10-1 , 1 10-2, 1 10-3.

Figure 2B illustrates the frame structure of a DL F-DPCH channel. The F-DPCH channel uses one SF256 code carrying 20 bits per slot. When the RL 140-1 , 140-2, 140-n is setup, the CNN 130 assigns to the UE 120 a chip-offset (a multiple of 256 chips) indicating the TPC bits the UE 120 has to listen to. Similarly the CNN 130 indicates to each cell in the active set of the UE 120, the chip-offset to be used for that specific UE 120. The NTPC bits is set to 2.

In current UMTS cellular system the F-DPCH can only be shared by 10 RLs 140-1 , 140-2, 140-n, for up to 10 UEs. Compared to DPCH the power and code consumption is lower, but it is still excessive compared to the benefit that may be derived from it, as the same result can be achieved in a more efficient way.

Figure 3 illustrates a scenario in a wireless communication network 100 wherein a UE 120 is in SHO, having a first RL 140-1 of a serving cell 310, associated with a first network node 1 10-1 , and a second RL 140-2 of a non-serving cell 320, associated with a second network node 1 10-2, in the active set of the UE 120.

According to some embodiments, a method is provided to decrease the amount of DL Frac- tional DPCH (F-DPCH) resources consumed by UEs 120 in SHO or SoHO by forcing the non-serving cell 320 to always transmit the power-up command (i.e. "1 ") to the UE 120 in SHO and SoHO. The actual power-control command (power-up or power-down) is thus dictated by the serving-cell 310 in the active set. This feature requires the UE 120 to support the Enhanced F-DPCH.

Additionally a method is provided for preventing UEs 120 which are in SHO and power controlled only by the serving from creating excessive interference to non-serving cells 320 in special cases like UL/ DL link imbalance. In the illustrated example, all RLs 140-2 of non-serving cell 320 are associated with incrementing power control signalling by associating them with the same set of TPC bits within the FDPCH slot 300-2, e.g. by applying the same offset. In this illustrated example, the last set of TPC bits of the FDPCH slot 300-2 is dedicated for an incrementing power control command, which is to be used by all UEs which have the non-serving cell 320 in their active set.

The RL 140-1 of the serving cell 310 is associated with the power control command based on pilot signal measurement in a distinct set of the FDPCH slot 300-1. Thereby various advantages are achieved. One advantage is that DL control signalling overhead for SHO and SoHO is reduced, specifically the consumption of F-DPCH resources is reduced. Thereby the DL capacity of the wireless communication network 100 is increased. Furthermore, the UL capacity of the wireless communication network 100 is increased by increasing the UL active set size (increased SHO ratio) without increasing the control overhead in DL thus without penalising the DL capacity.

These advantages are achieved by modifying the existing RL setup (specifically the F-DPCH signalling) for non-serving cells 320 of SHO and SoHO UEs 120.

Figure 4 illustrates an example of a method embodiment 400. The method embodiment 400 is performed in a CNN 130 in a communication network 100, for providing a power control command for at least one RL 140-1 , 140-2, 140-n associated with a UE 120. The UE 120 is wirelessly communicating with a serving cell 310 and at least one non-serving cell 320 of at least one network node 1 10-1 , 1 10-2, 1 10-3 in the communication network 100. In a first step 401 , the method 400 comprises checking if the non-HSDPA load exceeds a threshold limit. The threshold limit may be pre-set to e.g. about 50%, in a non-limiting example. When the threshold limit is exceeded, the method 400 is continued, otherwise the method 400 is discontinued, or put on hold. By defining a threshold limit and only performing the method 400 when the non-HSDPA load in the network 100 is high, i.e. exceeding the threshold limit, the method 400 may be performed only when more capacity is required in the network 100.

Further, the method 400 also comprises a second step 402, which in turn comprises sorting the RLs 140-1 , 140-2, 140-n in the active set of the UE 120 according to a criterion and assign an increasing index (RLindex) to each RL 140-1 , 140-2, 140-n, for every UE 120 controlled by this CNN 130. The RLindex = 1 , according to some embodiments.

In a subsequent step 403, a check is made for determining if the RL 140-1 , 140-2, 140- n is associated with a serving cell 310, or a non-serving cell 320.

For RLs 140-1 , 140-2, 140-n associated with any non-serving cells 320, the chip offset may be set to a reserved, predefined offset in step 404. Thereby the RLs 140-1 , 140-2, 140-n associated with this non-serving cell 320 all get assigned the same set of TPC bits.

In step 405, the TPC command of the set is set to an incrementing power command (independently of any actual UL received signal power measurements). However, when the RL 140-1 , 140-2, 140-n is associated with the serving cell 310, the chip offset may be set according to any standard defined method, based on UL received signal power measurements made by the serving cell 310, in a step 407.

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Furthermore, in step 406, a check is made if any more RLs 140-1 , 140-2, 140-n yet are comprised in the active set of RLs for the UE 120.

In step 408 of the loop, the RL index is increased by one, i.e. a move is made to the next RL 10 index.

Figure 5 illustrates an enhanced FDPCH slot 300. The FDPCH slot 300 comprises 9 sets of FDPCH sets of NTPC power control bits 510-0, 510-1 , 510-8, or Transmit Power Control (TPC) bits and also one Specific FDPCH set 510-9, which is dedicated for non-serving RLs

15 140-1 , 140-2, 140-n of UEs 120, which always comprises an incrementing TPC command. Such UE 120 obviously need to have the cell which control the FDPCH as non-serving cell 320. In this illustrated example, the Specific FDPCH set 510-9 is situated as the last set in the enhanced FDPCH slot 300. This is however only a non-limiting example, the Specific FDPCH set 510-9 may be situated at any position within the enhanced FDPCH slot 300, i.e.

20 having any arbitrary but predetermined offset. In this disclosure, the expressions power control bits and TPC bits may be used in parallel.

Thus, one specific set of TPC bits 510-9 of the ten sets of TPC bits 510-0, 510-1 , 510-9 carried by the Enhanced F-DPCH 300 during one slot is used as a shared resource by all 25 the RLs 140-1 , 140-2, 140-n which are controlled by non-serving cells 320, and associated with a plurality of UEs 120, in this illustration exemplified by the UE 5 120-5, UE 6 120- 6 and UE 7 120-7.

The set of TPC bits 510-9, which is shared between RLs 140-1 , 140-2, 140-n which are 30 controlled by non-serving cells 320, hereinafter is called Shared-FDPCH or S-FDPCH while a RL 140-1 , 140-2, 140-n to a non-serving cell 320 hereinafter is called non-serving RL.

The sharing of the FDPCH resource may be realised by reserving one set of NTPC bits and assigning to all non-serving RLs the same and appropriate chip-offset so that the non-serving 35 RLs use such set of NTPC bits, in Figure 5 denoted as the set of TPC bits 510-9. Further, the cell of the non-serving RL is configured to always send an incrementing power control command, command, to that UE 120, which is neutral compared to the TPC commands from the RL of the serving cell 310 and does not affect the Inner Loop Power Control (ILPC) of the serving cell 310.

Thus the power control commands of the non-serving RL do not influence the regulation of the transmission power of the UE 120, which is exclusively regulated by the ILPC of the serving cell 310.

The ILPC is sometimes also referred to as fast closed loop power control. The ILPC adjusts the output power of the UE 120 in accordance with one or more TPC commands received in the DL, in order to keep the received UL SIR at a predefined SIR target. The UE 120, upon receiving the TPC commands, the output power may be changed with a step size of 1 , 2 and 3 dB, in different embodiments in the slot immediately after having received the TPC command. The inner loop power control frequency is 1 500 Hz. Instead of estimated SIR and SIR target, any other similar measure may be utilised, such as e.g. Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR or S/N), Signal to Noise plus Interference Ratio (SNIR), Signal, Noise and Distortion ratio (SINAD), Signal-to-Quantization-Noise Ratio (SQNR), or any similar measurement or ratio related to a comparison of the power level of a desired signal with the level of undesired background noise.

Thus the serving cell may estimate SIR of the received uplink DPCH, generate TPC command and transmit the command once per slot according to the following rule: when the estimated SIR of the received UL signal exceeds SIR target, a decreasing TPC command is sent and in the opposite case, when the estimated SIR of the received UL signal is lower than the SIR target, an increasing TPC command is sent to the UE 120.

From the protocols 10.3.6.27 DL information for each radio link in 25.331 3GPP and/ or 10.3.6.23 DL F-DPCH info for each RL in 25.331 3GPP, it may be concluded that one FDPCH frame offset may be set for each RL 140-1 , 140-2, 140-n. This FDPCH frame offset decides the set of NTPC bits the UE uses. For an e-FDPCH the chip offset for different RLs of the same UEs does not need to be the same.

As a side note it is important to note that the same technique of defining the UE-specific offset in number of chips is used to configure the DPCH frame offset. On the other hand it is not recommended to have different offsets for different RLs using DPCCH to signal power control because the DL performance in this case would deteriorate. As an example, if the UE 120 has three RLs 140-1 , 140-2, 140-n, these three RLs 140-1 , 140-2, 140-n should use the same DPCH frame offset because the control information from such RLs 140-1 , 140- 2, 140-n is combined, and the way in which it is combined (the combination technique) depends on the control field.

In case of strong imbalance between UL and DL, i.e. that the serving cell in DL is different from the cell that is receiving the stronger signal in UL, a mean of coordination is provided in some embodiments, for coordinating between the two network nodes 1 10-1 , 1 10-2, 1 10-3 such that the power down commands to be sent by the non-serving cell 320 are relayed to the serving cell 310, or are translated into a dynamic offset to be applied to the Signal to Interference Ratio (SIR)-target of the serving cell 310.

This change is not expected to jeopardise the DL performance because the serving cell 310 is usually the cell which exhibits a higher measured SIR and is thus the one usually sending the power-down command.

An option to implement such offset may comprise increasing the offset until the number of power control down commands from the two cells 310, 320 are comparable over a reference period and decrease it otherwise in some embodiments.

Furthermore, in some embodiments, the UEs 120 which support the enhanced F-DPCH can add a RL 140-1 , 140-2, 140-n in UL to their active set without consuming any additional control resource in DL. Also, the UL active set may be increased in some embodiments, without having to consume additional FDPCH resources in DL, thus increasing the UL ca- pacity for such UEs 120 without any cost in terms of DL performance. This is beneficial because RLs 140-1 , 140-2, 140-n can be added to active set and combined to the serving RL 140-1 , 140-2, 140-n even beyond the 3 dB threshold for RL addition and beyond the conventional limitation of a maximum of 3 RLs for active set size. In this way more useful power in UL can be demodulated so that the UE transmission power as well as the inter-cell interference are decreased.

Figure 6A comprises a diagram which discloses an example of signal strength measurements made by the UE 120, of DL pilot signals transmitted over different respective RLs 140- 1 , 140-2, 140-n. Also, the 1A limit 610 and 1 B limit 620 are visualised together with the signal strength measurements over nine RLs 140-1 , 140-2, 140-n. The 1A limit 610 is the limit value for sending a request to the CNN 130 for adding a new RL 140-1 , 140-2, 140-n to the active set 600. The 1A limit 610 is determined as a difference in comparison with the received signal strength of the serving cell RL 630, such as e.g. -3 dB in the illustrated example. Such measurement report is called a 1A event report.

The 1 B limit 620 is correspondingly the limit value for sending a request to the CNN 130 for removing a RL 140-1 , 140-2, 140-n from the active set 600. The 1 B limit 620 is determined as a difference in comparison with the received signal strength of the serving cell RL 630, such as e.g. -6 dB in the illustrated example. Such measurement report is called a 1 B event report.

The 1A report and the 1 B report are defined by the 3GPP standard 25.331 . The 1A limit 610 and/ or the 1 B limit 620 may in some embodiments be dynamically adjusted, based on if enhanced transmission capacity is required in UL or in DL.

The active set size is in conventional solutions limited to a max number (typically 3) to avoid excessive consumption of DL control information. However, according to some embodiments, the active set size may be dynamically adjusted. The active set size may be increased in some embodiments (maybe even statically, once and for all, by setting higher values for 1 A, 1 B and the max allowed number of RLs) because there is no need to take into account the consumption of control capacity in DL.

Also, the active set 600 of RLs 140-1 , 140-2, 140-n is visualised. In the illustrated exam- pie, the active set 600 comprises two RLs: RL 1 and RL 4. This is only a non-limiting example.

Further, at the bottom of Figure 6A is the UL/ DL transmission illustrated. All DL data is transmitted over the serving cell RL 1 while UL data is transmitted both over RL 1 and RL 4. In the DL of RL 1 and RL 4 is control information transmitted such as e.g. TPC.

The illustrated example in Figure 6A is used as a starting point, or reference for comparison when the subsequent Figure 6B is discussed. But first the diagram of signal strength measurements will be further explained. The UE 120 in this example has nine RLs 140-1 , 140-2, 140-n in its monitored set of RLs. Thus the UE 120 is continuously measuring DL pilot signals over the nine RLs 140-1 , 140- 2, 140-n and compare them with the reference signal strength 630 of a DL pilot signal received over the serving cell RL 1 , and also with the 1A limit 610 and the 1 B limit 620.

In this non-limiting example, the 1A limit 610 is set to 3 dB below the reference signal strength 5 630 of the DL pilot signal received over the serving cell RL 1 . However, unlike conventional solutions, the 1A limit 610 may be dynamically adjusted to any value in some embodiments, such as e.g. set to a much larger value.

Further, in another non-limiting example, the 1 B limit 620 is set to 6 dB below the reference 0 signal strength 630 of the DL pilot signal received over the serving cell RL 1 . However, unlike conventional solutions, the 1 B limit 620 may be dynamically adjusted to any value, such as e.g. set to a much larger value.

Also, the active set size is limited to three RLs 140-1 , 140-2, 140-n. However, as only two5 RLs are fulfilling the signal strength requirements for entering the active set 600, the active set 600 is not limited by the active set size limit in this embodiment.

Thus, looking a bit closer at the diagram, the serving cell RL 1 has the strongest received signal strength. This may often be the case, however, any non-serving cell RL may at least0 temporarily have a stronger received signal strength, e.g. until a change of serving cell RL is made in case of SHO/ SoHO.

RL 2 in this example has a rather weak received signal strength about 10 dB below the serving cell RL strength 630.

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RL 3 has a received signal strength stronger than the 1 B limit 620, i.e. the limit for being excluded from the active set 600, but has not achieved the 1A limit 610. Thus RL 3 does not fulfil the requirements for inclusion into the active set 600 with the current 1A limit. 0 RL 4 has a received signal strength stronger than the 1A limit 610 i.e. the limit for being included in the active set 600, thus RL 4 is included in the active set 600.

RL 5 has a received signal strength stronger than the 1 B limit 620. However, as RL 5 has not achieved the 1A limit 610, RL 5 does not fulfil the requirements for inclusion into the5 active set 600 with the current 1A limit. RL 6 has a decreasing received signal strength trend, currently below the 1 B limit 620. RL 6 does thereby not fulfil the requirements for being included in the active set 600.

RL 7 and RL 8 have very weak received signal strengths, far below the 1A limit 610 for inclusion into the active set 600.

RL 9 has an increasing trend, almost but not quite achieving the 1A limit 610. Thus RL 9 is currently not included in the active set 600, but will probably be if the increasing trend persists.

At the bottom of Figure 6A, it is illustrated that UL data is transmitted over two RLs, RL 1 and RL 4. In the opposite DL direction, control information is sent over two RLs (RL 1 and RL 4).

Figure 6B is illustrating the same diagram and other illustrations as illustrated in the previ- ously described Figure 6A. The received signal strengths of all DL signals over the RLs 140- 1 , 140-2, 140-n are identical with the situation illustrated in Figure 6A.

In some embodiments, user data is carried over the shared HSDPA channel, while control data (mainly TPC commands) are carried over the e-FDPCH. If power control from non- serving RLs are not utilised or valid any longer, all TPC commands from such non-serving RLs in a specific part of the e-FDPCH.

This means that for every RL that is added, there is no consumption of DL resources, therefore there is practically no harm from adding it. In other words it will improve the UL perfor- mance (because more RLs are used in UL for listening to the UE), but no price has to be paid as the TPC bits are put on the same specific part of the e-FDPCH.

Therefore the added value of this patent is two-fold: On one side control channel capacity in DL is saved, which can therefore use for user data. On the other side UL capacity may be improved by increasing various thresholds such as 1 A limit, 1 B limit and max number of RLs allowed in the active set size, because anyway no additional resources are required in the DL, because the TPC bits are going to be carried in the same specific "slot" of the e-FDPCH. "Slot" may be put in quotes because it seems there is no word to indicate a specific set of TPC bits carried by the e-FDPCH.

In this example, the 1A limit value 610 for transmitting a 1A report for requesting introduction of a RL 140-1 , 140-2, ... , 140-n that has a received signal strength stronger than the 1 A limit value 310, has been changed from -3 dB to -5 dB, as counted from the received signal strength of the serving cell RL 600.

Also in this example, the 1 B limit value 620 for transmitting a 1 B report for requesting removal of a RL 140-1 , 140-2, 140-n that has a received signal strength weaker than the 1 B limit value 620, has been changed from -6 dB to -8 dB, as counted from the received signal strength of the serving cell RL 600.

In addition, also the maximum number of RLs 140-1 , 140-2, 140-n allowed in the active set 600 has been altered from three (in the example illustrated in Figure 6A) to five.

Thus the threshold for being entered into the active set 300 has been decreased. As illustrated in the diagram, RL 5 now has a stronger received signal than the 1A limit value 610. Also RL 9 has a stronger received signal than the 1A limit value 610.

Thereby more RLs 140-1 , 140-2, 140-n are allowed in the active set 600 of the UE 120. Before the change, the active set 600 comprised RL1 and RL 4, as illustrated in Figure 6A. After the changes of the 1 A value, the 1 B value and the maximum limit of RLs in the active set 600, the active set 600 comprises RL 1 , RL 4, RL 5, RL 6, and RL 9.

The thereby achieved effect is illustrated at the bottom of Figure 6B, i.e. that UL data is transmitted over five RLs (RL 1 , RL 4, RL 5, RL 6 and RL 9) instead of the previous two RLs (RL 1 and RL 4). In the opposite DL direction, power control information is sent over five RLs instead of the previous two RLs. Thus more resources are used in the DL in comparison with the situation before the alteration of the 1A limit 610, the 1 B limit 620 and the increase of the maximum numbers of RLs in the active set 600. However, as the presumption was that capacity was available in the DL, but there was a congestion in the UL, the UL congestion problem is solved, or at least somewhat diminished, while the additional DL power control signalling does not introduce any problem as there is free capacity to use in DL.

As illustrated at the bottom illustration, the DL power control from the first RL is carried on the standard assigned "slot" 510-1 of the e-FDPCH 300, while the DL power control from the other RLs 4, 5, 6, 9 are carried all on the same slot 510-9 of the e-FDPCH 300. In conventional methods, the maximum active set size and the threshold levels for requesting entrance and exclusion, respectively, from the active set are fixed. This creates a problem when the capacity requirements in UL and DL are imbalanced. This results in low capacity. However, thanks to the introduction of flexible and dynamically adjustable modification of the active set of RLs, based on a detected constraint in either UL or DL, signalling resources may be allocated from UL to DL and vice versa. By the provided dynamical management of the active set size, system resources are better used and adapted to the resource demands.

Thereby the signalling within the communication network 100 is improved thanks to the added flexibility in allocation of signalling resources from DL to UL, and vice versa. Figure 7 is a flow chart illustrating embodiments of a method 700 for use in a CNN 130 in a communication network 100, for providing a power control command for at least one RL 140- 1 , 140-2, 140-n associated with a UE 120. The power control command may be a Transmit Power Control (TPC) command, comprising either an incrementing command or a decreasing command. The UE 120 is wirelessly communicating with a serving cell 310 and at least one non-serving cell 320 of at least one network node 1 10-1 , 1 10-2, 1 10-3 in the communication network 100.

The network node 1 10-1 , 1 10-2, 1 10-3 may comprise a Node B (NB) in some embodiments. The UE 120 may comprise e.g. a mobile station, cell phone or similar, or a wearable compu- ting device, mobile sensor or similar.

Thus in some embodiments, the CNN 130 may be distinct from the network node 1 10-1 , 1 10-2, 1 10-3 in the communication network 100. Further, the communication network 100 may be based on e.g. 3GPP Universal Mobile Telecommunications System (UMTS) network or any similar or related communication technology concept. The CNN 130 may be a Radio Network Controller (RNC) in some embodiments and the network node 1 10-1 , 1 10-2, 1 10-3 may be a Node B.

However, the CNN 130 may in some alternative embodiments be comprised in the network node 1 10-1 , 1 10-2, 1 10-3, or in the RNC in the communication network 100.

To appropriately provide a power control command for at least one RL 140-1 , 140-2, ... , 140- n associated with a UE 120, the method 700 may comprise a number of actions 701 -707. It is however to be noted that any, some or all of the described actions 701 -707, may be per- formed in a somewhat different chronological order than the enumeration indicates. At least some of the actions 701 -707 may be performed simultaneously or even be performed in an at least partly reversed order according to different embodiments. Further, it is to be noted that some actions may be performed in a plurality of alternative manners according to different embodiments, and that some such alternative manners may be performed only within some, but not necessarily all embodiments. Further, the authentication according to at least some of the performed actions 701 -707 may be periodically repeated in some embodiments.

In some alternative embodiments, the method 700 may only be performed when at least one cell 310, 320 has a load exceeding a threshold limit.

According to some embodiments, the method 700 is only performed for the UE 120, when the UE 120 is capable of utilising different sets of power control commands 510-0, 510-1 , 510-2, 510-3, 510-4, 510-5, 510-6, 510-7, 510-8, 510-9 for different RLs 140-1 , 140-2, 140-n comprised in an active set 600 of RLs 140-1 , 140-2, 140-n. Thus, in some embodiments, the method 700 may only be performed when the UE 120, the network nodes 1 10- 1 , 1 10-2, 1 10-3 and/ or the CNN 130 are configured to operate according to 3GPP Release 7 of UMTS.

According to some embodiments, the method 700 may comprise dedicating one set of power control bits 510-9 comprised in a DL dedicated physical channel slot 300, to RLs 140-1 , 140- 2, 140-n communicating with any non-serving cell 320.

The DL Dedicated Physical Channel may in some embodiments be an enhanced Fractional Dedicated Physical Channel (e-FDPCH) as defined by the 3GPP Release 7 or later of the specification of UMTS. The dedicated set of power control commands 510-9 may be situated at any arbitrary offset position within the DL dedicated physical channel slot 300.

The one set of power control bits 510-9, or TPC bits, may correspond to one power control command. The same power control command is used for all other non-serving RLs, and this is what provides the saving of control resources.

According to some embodiments, the method 700 further optionally may comprise setting the dedicated 701 set of power control bits 510-9 to an incrementing power control command. The incrementing power control command may be 1 , or a sequence of 1 , such as e.g. two bits of 1 when two bits are carried per slot in the DL dedicated physical channel, or alternatively four bits of 1 when four bits are carried per slot in the DL dedicated physical channel, eight bits of 1 when eight bits are carried per slot in the DL dedicated physical channel, etc.

The reason is that a different number of bits 2, 4 or 8 etc. may be used in the DPCCH field of the DL DPCH depending on the SF and the slot format, while in the e-FDPCH the number of TPC bits may consequently be 2. The method 700 comprises the following actions:

Action 701 comprises dedicating one set of power control bits 510-9 comprised in a DL dedicated physical channel slot 300, to RLs 140-1 , 140-2, 140-n communicating with any non-serving cell 320.

The DL Dedicated Physical Channel may in some embodiments be an enhanced Fractional Dedicated Physical Channel, e-FDPCH, as defined by the 3GPP Release 7 or later of the specification of UMTS. The dedicating one set of power control commands 510-9 may be situated at any arbitrary offset position within the DL dedicated physical channel slot 300.

The one set of power control bits 510-9, or TPC bits, may correspond to one power control command. The same power control command is used for all other non-serving RLs, and this is what provides the saving of control resources.

Action 702 comprises setting the dedicated 701 set of power control bits 510-9 to an incrementing power control command. The incrementing power control command may be 1 , or a sequence of 1 , such as e.g. two bits of 1 when two bits are carried per slot in the DL dedicated physical channel, or alternatively four bits of 1 when four bits are carried per slot in the DL dedicated physical channel, eight bits of 1 when eight bits are carried per slot in the DL dedicated physical channel, etc. The reason is that a different number of bits 2, 4 or 8 etc. may be used in the DPCCH field of the DL DPCH depending on the SF and the slot format, while in the e-FDPCH the number of TPC bits may consequently be 2. Action 703 comprises detecting at least one RL 140-1 , 140-2, 140-n on which the UE 120 is communicating with any non-serving cell 320. In some embodiments, several such RLs 140-1 , 140-2, 140-n communicating with non- serving cells 320 may be detected.

Action 704 comprises assigning the dedicated 701 set of power control bits 510-9 to the detected 703 at least one RL 140-1 , 140-2, 140-n on which the UE 120 is communicating with any non-serving cell 320.

Thus power control commands may be provided for RLs 140-1 , 140-2, 140-n associated with a plurality of UEs 120, communicating with any non-serving cell 320, by assigning the dedicated set of power control bits 510-9 to the RLs 140-1 , 140-2, 140-n on which the plurality of UEs 120 are communicating with any non-serving cell 320.

The dedicated set of power control bits 510-9 is shared by a plurality of non-serving RLs, that is, at least two non-serving RLs. Thus the disclosed method 700 is in particular beneficial in a scenario with a plurality of UEs 120 which are in SHO or SoHO.

Action 705 is comprised only in some optional embodiments. The optional action 705 may comprise detecting when a difference between the received UL signal strength as perceived by the non-serving cell 320 and the received UL signal strength as perceived by the serving cell 310 exceeds a threshold value. The threshold value may be 5%, 10% or any value of similar size.

Action 706 is comprised only in some optional embodiments. The optional action 706 may comprise instructing the UE 120 to decrease the transmission signal strength, based on the estimated UL SIR as perceived by the non-serving cell 320, via a transmission power com- mand transmitted by the serving cell 310.

In some embodiments, the instruction to decrease the transmission signal strength of the UE 120 comprises an offset value, based on the detected 705 difference between the estimated UL SIR as perceived by the non-serving cell 320 and the estimated UL SIR as perceived by the serving cell 310. The offset value may be a positive or negative value depending on how positive/ negative direction is defined. In other words, if the SIR estimated at the non-serving cell 320 is larger than the target by a certain threshold, an offset value may be applied to the SIR target of the serving cell 310 so that the serving cell 310 starts transmitting negative power control commands, as the SIR target requirements fictitiously has been lowered. Then, the offset may be made larger, i.e. by adjusting the SIR target until the difference in number of power control down commands over a certain reference period is smaller than a threshold level.

According to some embodiments, the offset value may be adjusted until the difference in number of power control down commands from the non-serving cell 320 and the serving cell 310 over a reference period is smaller than a threshold level.

Thereby, the power control commands may be transmitted from the non-serving cell 320 to the UE 120, although the inner loop power control of the serving cell 310 is considerably much faster than the transmission time over the network 100 from the non-serving cell 320 to the serving cell 310 via the CNN 130.

Action 707 comprises providing the downlink dedicated physical channel slot 300 to the UE 120. According to some alternative embodiments, the UE 120 may be permitted to increase the number of RLs 140-1 , 140-2, 140-n in an active set 600 of RLs 140-1 , 140-2, 140-n, by: controlling the number of RLs 140-1 , 140-2, 140-n in the active set 600; increasing a 1 A threshold value 610, with respect to a serving cell RL strength 630, for transmitting a 1A report from the UE 120 to the CNN 130; and/ or increasing a 1 B threshold value 620, with respect to a serving cell RL strength 630, for transmitting a 1 B report from the UE 120 to the CNN 130.

Figure 8 illustrates an embodiment of a CNN 130, in a communication network 100, for providing a power control command for at least one RL 140-1 , 140-2, 140-n associated with a UE 120. The UE 120 may be wirelessly communicating with a serving cell 310 and at least one non-serving cell 320 of at least one network node 1 10-1 , 1 10-2, 1 10-3 in the communication network 100.

The CNN 130 may be distinct from the at least one network node 1 10-1 , 1 10-2, 1 10-3 in the communication network 100 in some embodiments. The communication network 100 may be a Universal Mobile Telecommunications System (UMTS) network. The CNN 130 may be comprised in a RNC in some embodiments and the at least one network node 1 10-1 , 1 10-2, 1 10-3 may be a Node B.

The CNN 130 may in some embodiments be comprised in the at least one network node 1 10-1 , 1 10-2, 1 10-3 in the communication network 100.

For enhanced clarity, any internal electronics or other components of the CNN 130, not completely indispensable for understanding the herein described embodiments have been omitted from Figure 8.

The CNN 130 is configured for performing the method 700, according to any, some, all, or at least one of the enumerated actions 701 -707, according to some embodiments. Thus the CNN 130 comprises a processing unit 820, configured to dedicate one set of power control bits 510-9 comprised in a downlink dedicated physical channel slot 300, for RLs 140-1 , 140- 2, 140-n communicating with any non-serving cell 320. The processing unit 820 is also configured to set the dedicated set of power control bits 510-9 to an incrementing power control command. Also, the processing unit 820 is further configured to detect at least one RL 140-1 , 140-2, 140-n on which the UE 120 is communicating with any non-serving cell 320. Further, the processing unit 820 is configured to assign the dedicated set of power control bits 510-9 to the detected at least one RL 140-1 , 140-2, 140-n on which the UE 120 is communicating with any non-serving cell 320. The processing unit 820 is furthermore configured to provide the downlink dedicated physical channel slot 300 to the UE 120.

Further, the processing unit 820 may be configured to detect that the UE 120 is wirelessly communicating with a serving cell 310 and at least one non-serving cell 320 of at least one network node 1 10-1 , 1 10-2, 1 10-3 in the communication network 100, in some embodiments.

The processing unit 820 may be further configured to determine when at least one cell 310, 320 in the communication network 100 has a load exceeding a threshold limit; and provide the downlink dedicated physical channel slot 300 to the UE 120 only when at least one cell 310, 320 has a load exceeding the threshold limit. The dedicated set of power control bits 510-9 may be assigned not just to the UE 120 but to the UE on the RL which connects such UE to the overloaded cell. The DL dedicated physical channel may be an enhanced Fractional Dedicated Physical Channel (e-FDPCH) as defined by the 3GPP, Release 7 or later of the specification of UMTS. According to some embodiments, the processing unit 820 may be further configured to assign the dedicated set of power control bits 510-9 to the detected at least one RL 140-1 , 140- 2, 140-n on which the UE 120 is communicating with any non-serving cell 320, only when the UE 120 is capable of utilising different sets of power control commands 510-0, 510-1 , 5 510-2, 510-3, 510-4, 510-5, 510-6, 510-7, 510-8, 510-9 for different RLs 140-1 , 140-2, 140-n comprised in an active set of RLs 600.

In some further embodiments, the processing unit 820 may be configured to detect when a difference between the estimated uplink SIR as perceived by the non-serving cell 320 and 10 the estimated uplink SIR as perceived by the serving cell 310 exceeds a threshold value.

The processing unit 820 may also be configured to instruct the UE 120 to decrease the transmission signal strength, based on the estimated uplink SIR as perceived by the non- serving cell 320, via a transmission power command transmitted by the serving cell 310.

15 Also, the processing unit 820 may furthermore be configured to instruct the UE 120 to decrease the transmission signal strength by setting an offset value, based on the detected difference between the estimated uplink SIR as perceived by the non-serving cell 320 and the estimated uplink SIR as perceived by the serving cell 310, in some embodiments.

20 The processing unit 820 may in some embodiments be configured to adjust the offset value until the difference in number of power control down commands from the non-serving cell 320 and the serving cell 310 over a reference period is smaller than a threshold level.

In some embodiments, the processing unit 820 may also be configured to permit the UE 120 25 to increase the number of RLs 140-1 , 140-2, 140-n in an active set 600 of RLs 140-1 , 140-2, 140-n, compared to an initial number of RLs 140-1 , 140-2, 140-n, by controlling the number of RLs 140-1 , 140-2, 140-n in the active set 600; and/ or increasing a 1A threshold value 610, with respect to a serving cell RL strength 630, for transmitting a 1A report from the UE 120 to the CNN 130; and/ or increasing a 1 B threshold value 620, with 30 respect to a serving cell RL strength 630, for transmitting a 1 B report from the UE 120 to the CNN 130.

Furthermore, in some embodiments, the processing unit 820 may be configured to provide power control command for RLs 140-1 , 140-2, 140-n associated with a plurality of UEs 35 120, communicating with any non-serving cell 320, by assigning the dedicated set of power control bits 510-9 to the RLs 140-1 , 140-2, 140-n on which the plurality of UEs 120 are communicating with any non-serving cell 320. Such processing unit 820 may comprise one or more instances of a processing circuit, i.e. a Central Processing Unit (CPU), a processor, a processing circuit, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The herein utilised expression "processing unit" may thus represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones enumerated above.

The CNN 130 may further comprise a receiving unit 810, configured to receive information from the network nodes 1 10-1 , 1 10-2, 1 10-3 over a wired or wireless interface. The received information may comprise for example signal strength measurements of DL network node signals made by the UE 120.

Also, the CNN 130 may comprise a transmitter 830 configured to transmit information to the network nodes 1 10-1 , 1 10-2, 1 10-3 over a wired or wireless interface. The transmitted information may comprise e.g. control signalling to the network nodes 1 10-1 , 1 10-2, 1 10-3, or to the UE 120, via the network nodes 1 10-1 , 1 10-2, 1 10-3.

Furthermore, the CNN 130 may further comprise at least one memory 840, according to some embodiments. The optional memory 840 may comprise a physical device utilised to store data or programs, i.e., sequences of instructions, on a temporary or permanent basis. According to some embodiments, the memory 840 may comprise integrated circuits comprising silicon-based transistors. Further, the memory 840 may be volatile or non-volatile. The above described actions 701 -707 to be performed in the CNN 130 may be implemented through the one or more processing units 820 in the CNN 130, together with computer program product for performing at least some of the functions of the actions 701 -707. Thus a computer program comprising program code may perform the method 700 according to any, at least some, or all of the functions of the actions 701 -707 for providing a power control command for at least one RL 140-1 , 140-2, 140-n associated with the UE 120, when the computer program is loaded into the processing unit 820 of the CNN 130.

Furthermore, the method 700 according to at least some of the actions 701 -707 may be implemented in a computer program, having code means, which when run by the processing unit 820 in the CNN 130, causes the processing unit 820 to execute at least some of the actions 701 -707 of the method 700. The computer program is comprised in a computer readable medium of a computer program product. The computer readable medium may comprise essentially any memory, such as a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), an EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), a hard disk drive or any other appropriate medium such as a disk or tape that may hold machine readable data in a non-transitory manner. The computer pro- gram product may furthermore be provided as computer program code on a server and downloaded to the CNN 130 remotely, e.g., over an Internet or an intranet connection.

Further Figure 8 discloses a UE 120, in a communication network 100, for wireless communication with a serving cell 310 and at least one non-serving cell 320 of at least one network node 1 10-1 , 1 10-2, 1 10-3 in the communication network 100. The UE 120 is assigned a downlink dedicated physical channel slot from the CNN 130.

Further a system is provided in a communication network 100, for providing a power control command for at least one Radio Link, RL 140-1 , 140-2, 140-n associated with a User Equipment, UE 120. The UE 120 is wirelessly communicating with a serving cell 310 and at least one non-serving cell 320 of at least one network node 1 10-1 , 1 10-2, 1 10-3 in the communication network 100. The system comprises a CNN 130 and a UE 120.

The terminology used in the description of the embodiments as illustrated in the accompa- nying drawings is not intended to be limiting of the described method 700; the CNN 130; the network node 1 10-1 , 1 10-2, 1 10-3, UE 120, the computer program and/ or the system. Various changes, substitutions and/ or alterations may be made, without departing from the invention as defined by the appended claims. As used herein, the term "and/ or" comprises any and all combinations of one or more of the associated listed items. The term "or" as used herein, is to be interpreted as a mathematical OR, i.e., as an inclusive disjunction; not as a mathematical exclusive OR (XOR), unless expressly stated otherwise. In addition, the singular forms "a", "an" and "the" are to be interpreted as "at least one", thus also possibly comprising a plurality of entities of the same kind, unless expressly stated otherwise. It will be further understood that the terms "includes", "comprises", "including" and/ or "comprising", specifies the presence of stated features, actions, integers, steps, operations, elements, and/ or components, but do not preclude the presence or addition of one or more other features, actions, integers, steps, operations, elements, components, and/ or groups thereof. A single unit such as e.g. a processor may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/ distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms such as via Internet or other wired or wireless communication system.

Claims

1 . A controlling network node, CNN (130), in a communication network (100), for providing a power control command for at least one Radio Link, RL (140-1 , 140-2, 140- n) associated with a User Equipment, UE (120), wherein the CNN (130) comprises:

a processing unit (820), configured to

dedicate one set of power control bits (510-9) comprised in a downlink dedicated physical channel slot (300), for RLs (140-1 , 140-2, 140-n) communicating with any non- serving cell (320);

set the dedicated set of power control bits (510-9) to an incrementing power control command;

detect at least one RL (140-1 , 140-2, 140-n) on which the UE (120) is communicating with any non-serving cell (320);

assign the dedicated set of power control bits (510-9) to the detected at least one RL (140-1 , 140-2, 140-n) on which the UE (120) is communicating with any non-serving cell (320); and

provide the downlink dedicated physical channel slot (300) to the UE (120).

2. The CNN (130) according to claim 1 , wherein the processing unit (820) is further configured to:

detect that the UE (120) is wirelessly communicating with a serving cell (310) and at least one non-serving cell (320) of at least one network node (1 10-1 , 1 10-2, 1 10-3) in the communication network (100).

3. The CNN (130) according to any of claim 1 or claim 2, wherein the processing unit (820) is further configured to:

determine a cell load exceeding a threshold limit for the cell (310, 320) in the communication network (100); and

provide the downlink dedicated physical channel slot (300) to the UE (120) in the cell (310, 320) has a load exceeding the threshold limit.

4. The CNN (130) according to any of claims 1 -3, wherein the processing unit (820) is further configured to:

assign the dedicated set of power control commands (510-9) to the detected RL (140-1 , 140-2, 140-n) on which the UE (120) is communicating with any non-serving cell (320), only when the UE (120) is capable of utilising different sets of power control commands (510-0, 510-1 , 510-2, 510-3, 510-4, 510-5, 510-6, 510-7, 510-8, 510-9) for different RLs (140- 1 , 140-2, 140-n) comprised in an active set of RLs (600).

5. The CNN (130) according to any of claims 1 -4, wherein the processing unit (820) is further configured to:

detect when a difference between

an estimated uplink Signal-to-lnterference Ratio, SIR, as perceived by the non-serving cell (320) and

an estimated uplink SIR as perceived by the serving cell (310) exceeds a threshold value; and

instruct the UE (120) to decrease the transmission signal strength, based on the estimated uplink SIR as perceived by the non-serving cell (320), via a transmission power command transmitted by the serving cell (310).

6. The CNN (130) according to claim 5, wherein the processing unit (820) is further configured to:

instruct the UE (120) to decrease the transmission signal strength by setting an offset value, based on the detected difference between the estimated uplink SIR as perceived by the non-serving cell (320) and the estimated uplink SIR as perceived by the serving cell (310).

7. The CNN (130) according to claim 6, wherein the processing unit (820) is further configured to:

adjust the offset value until the difference in number of power control down commands from the non-serving cell (320) and the serving cell (310) over a reference period is smaller than a threshold level.

8. The CNN (130) according to any of claims 4-7, wherein the processing unit (820) is further configured to:

permit the UE (120) to increase the number of RLs (140-1 , 140-2, 140-n) in an active set (600) of RLs (140-1 , 140-2, 140-n), compared to an initial number of RLs (140- 1 , 140-2, 140-n), by:

controlling the number of RLs (140-1 , 140-2, 140-n) in the active set (600); increasing a 1A threshold value (610), with respect to a serving cell RL strength (630), for transmitting a 1A report from the UE (120) to the CNN (130); or increasing a 1 B threshold value (620), with respect to a serving cell RL strength (630), for transmitting a 1 B report from the UE (120) to the CNN (130).

9. The CNN (130) according to any of claims 1 -8, wherein the CNN (130) is distinct from the at least one network node (1 10-1 , 1 10-2, 1 10-3) in the communication network (100); and wherein the communication network (100) is a Universal Mobile Telecommunications System, UMTS, network; the CNN (130) is a Radio Network Controller, RNC; and the at least one network node (1 10-1 , 1 10-2, 1 10-3) is a Node B.

10. The CNN (130) according to any of claims 1 -9, wherein the downlink dedicated physical channel is an enhanced Fractional Dedicated Physical Channel, e-FDPCH, as defined by the third Generation Partnership Project, 3GPP, Release 7 or later of the specifica- tion of UMTS.

1 1 . The CNN (130) according to any of claims 1 -10, wherein the CNN (130) is comprised in the at least one network node (1 10-1 , 1 10-2, 1 10-3) in the communication network (100).

12. The CNN (130) according to any of claims 1 -1 1 , configured to provide power control command for RLs (140-1 , 140-2, 140-n) associated with a plurality of UEs (120), communicating with any non-serving cell (320), by assigning the dedicated set of power control bits (510-9) to the RLs (140-1 , 140-2, 140-n) on which the plurality of UEs (120) are communicating with any non-serving cell (320).

13. A method (700) in a controlling network node, CNN (130), in a communication network (100), for providing a power control command for at least one Radio Link, RL (140-1 , 140-2, 140-n) associated with a User Equipment, UE (120), wherein the method (700) comprises:

dedicating (701 ) one set of power control bits (510-9) comprised in a downlink dedicated physical channel slot (300), to RLs (140-1 , 140-2, 140-n) communicating with any non-serving cell (320);

setting (702) the dedicated (701 ) set of power control bits (510-9) to an incrementing power control command;

detecting (703) at least one RL (140-1 , 140-2, 140-n) on which the UE (120) is communicating with any non-serving cell (320);

assigning (704) the dedicated (701 ) set of power control bits (510-9) to the detected (703) at least one RL (140-1 , 140-2, 140-n) on which the UE (120) is communicating with any non-serving cell (320);

providing (707) the downlink dedicated physical channel slot (300) to the UE (120).

14. A computer program comprising program code for performing a method (700) according to claim 13, when the computer program runs on a computer.

15. A User Equipment, UE, (120) in a communication network (100), for wireless com- 5 munication with a serving cell (310) and at least one non-serving cell (320) of at least one network node (1 10-1 , 1 10-2, 1 10-3) in the communication network (100), wherein the UE (120) is assigned a downlink dedicated physical channel slot from the controlling network node, CNN (130) according to any of claims 1 -12.

10 16. A system in a communication network (100), for providing a power control command for at least one Radio Link, RL (140-1 , 140-2, 140-n) associated with a User Equipment, UE (120), wherein the UE (120) is wirelessly communicating with a serving cell (310) and at least one non-serving cell (320) of at least one network node (1 10-1 , 1 10-2, 1 10-3) in the communication network (100), comprising:

15 a CNN (130) according to any of claims 1 -12; and

a UE (120) according to claim 15.