RU2575386C2 - General reconfiguration of radio interface - Google Patents

Abstract

FIELD: radio engineering; communication.

SUBSTANCE: invention relates to the methods of request and making a general reconfiguration of the radio interface as well as to the base station and user equipment. Method of request for general reconfiguration of the radio interface that shall be carried out by every member of the group of user equipments from the set of user equipments supported by the base station in a wireless communication system, multicarrier, comprising: determining the general reconfiguration of the radio interface that shall be carried out by every member of the group of user equipments; general reconfiguration of the radio interface is encoded in the payload field of command of a high speed shared control channel (HS-SCCH); encoding a designation in HS-SCCH command, the designation is to associate this HS-SCCH command with a group of user equipments, and transmitting the HS-SCCH command to the set of user equipments supported by the base station.

EFFECT: technical result is to reduce the time required to perform reconfiguration, and to minimize the amount of the resources used.

15 cl, 4 dwg

Description

FIELD OF THE INVENTION

The present invention relates to a method for requesting a general reconfiguration of a radio interface, a base station, a method for performing a general reconfiguration of a radio interface, user equipment, and computer software products.

BACKGROUND

Single carrier wireless communication systems are well known. In these well-known systems, they provide radio coverage for user equipment, such as mobile phones, by geographic area. Base stations are located in each geographic area to provide the required radio coverage. User equipment in this area, served by the base station, receives information and data from the base station and transmits information and data to the base station. In a high speed downlink packet access (HSDPA) communication network, data and information is sent between the user equipment and the base station in radio frequency carrier data packets.

The information and data transmitted by the base station to the user equipment is located on radio frequency carriers, known as downlink carriers. Information and data transmitted by the user equipment of the base station are located on radio frequency carriers, known as uplink carriers.

In known single-carrier wireless communication systems, user equipment can move between geographic areas of coverage of a base station. The service provided by the user equipment is controlled by a radio network controller (RNC). The RNC communicates with the user equipment and base stations and determines which base station each user equipment is initially connected to. In this case, the RNC performs control and communication functions with the base station and user equipment when the user equipment moves from a geographical area served by one base station to a geographical area served by another base station.

It has been proposed to allow each base station and user equipment to transmit simultaneously on more than one carrier. Moreover, it has been proposed to allow user equipment and base stations to receive simultaneously on more than one carrier. Each carrier, both uplink and downlink, is usually independently controlled in terms of power by the base station. The provision of more than one downlink carrier, for example, on four frequency carriers, makes it possible to increase the data rate of user equipment. Networks with more than two carriers may be referred to as multi-cell high speed downlink packet access (MC-HSDPA) networks. The term "multi-carrier" network, as used herein, is intended to encompass the case where two (eg, two-cell HSDPA and two-cell HSUPA), three, four or more carriers of a downlink (or uplink) are provided for the communication network.

Providing multicarrier functionality may have concomitant problems. Accordingly, it is desirable to improve the operation of a wireless communication network having multi-carrier functionality.

SUMMARY OF THE INVENTION

According to a first aspect, there is provided a method for requesting a general reconfiguration of a radio interface to be made by each of a group of user equipments from a plurality of user equipments supported by a base station in a multi-carrier wireless communication network, the method comprising the steps of: determining a general reconfiguration of the radio interface to be done by each from a group of user equipment; encoding a general reconfiguration of the radio interface in a payload field of a high speed shared control channel (HS-SCCH) command; encoding, in the HS-SCCH command, an indication associating the HS-SCCH command with a group of user equipments; and transmitting the HS-SCCH command to a plurality of user equipments supported by the base station.

The first aspect recognizes that one problem with the existing multi-carrier functionality is that, if necessary, reconfigure the radio interface between the user equipment and the base station, for example, to save energy, reduce interference, or for other reasons, this can only be done by sending a message to each from user equipments in turn, asking them to reconfigure their radio interfaces. It should be noted that sending such a message to each user equipment takes turns and consumes resources. This can lead to a decrease in the ability to take advantage of any benefit that this reconfiguration can offer.

Accordingly, a determination can be made about the need to reconfigure the radio interface, which is common to a group of user equipment supported by the base station. A user equipment group may be a subset of all user equipment supported by a base station. The reconfiguration may be the same reconfiguration, which must be performed by all user equipments in this group. The reconfiguration details may then be encoded in the HS-SCCH command, for example, in a payload field. Accordingly, the payload field may include an indication of the reconfiguration of the radio interface to be performed by each user equipment in the group. It should be appreciated that any suitable encoding techniques may be used to encode reconfiguration, which must be performed by a group of user equipments. The indication may also be encoded in the HS-SCCH command, which associates this command with a predefined group of user equipments. It should be appreciated that this guidance helps distinguish the HS-SCCH command for a group of user equipments from existing HS-SCCH commands for individual user equipments. The indication may also indicate which of the user equipment groups this HS-SCCH command is intended for. This HS-SCCH command may then be transmitted to a plurality of user equipment supported by the base station.

Therefore, it can be seen that the HS-SCCH command can be transmitted to a group of user equipments. This prevents the need to transmit individual messages to each of these user equipments. The HS-SCCH command can identify which group of user equipments this message is intended to, thus allowing user equipments outside this group to ignore this message. However, the user equipment included in the group can then make the requested changes to the radio interface, which will then be performed jointly for all user equipment in the group. It can be said differently that each user equipment in the group will carry out the requested change. Consequently, a single message can be sent to a group of user equipments instructing this group of user equipments to make a general reconfiguration of their radio interfaces, which reduces the amount of time required to complete the reconfiguration and minimizes the amount of resources used to complete the reconfiguration.

In one embodiment, a group of user equipments is in a dedicated channel state for a cell (Cell_DCH), and a general reconfiguration of the radio interface comprises at least one of activating at least one carrier, deactivating at least one carrier, primary carrier changes, serving cell changes, switching between normal transmission and intermittent transmission, and switching between normal reception and intermittent reception. Accordingly, the user equipment may operate in the CELL_DCH state in which high throughput is required, and thus fast changes to the radio interface may also be required to support this high throughput. For groups of user equipments in CELL_DCH state, it may be possible to activate or deactivate carriers, change the primary carrier, change the serving cell, switch to discontinuous reception or transmission mode and vice versa, or perform other reconfigurations of the radio interface. Thus, it can be seen that it is possible to deactivate or activate aspects of a large group of user equipment very quickly. For example, a base station may deactivate a single secondary frequency for a group or all groups of user equipment to implement interference management or energy conservation. In the event of energy conservation, the base station may, due to low traffic, wish to turn off one of its carriers, thus deactivating the secondary carriers for a group or all groups of user equipment.

In one embodiment, the step of encoding the indication comprises: adding a modified cyclic redundancy check field to the HS-SCCH command, wherein the modified cyclic redundancy check field is derived from at least one field of the HS-SCCH command, and the identifier is common to groups of user equipment. Accordingly, a modified cyclic redundancy check field may be added to the HS-SCCH command. This modified cyclic redundancy check field can be calculated using an identifier that is common to all user equipments in the group. In embodiments, such a common identifier may be a secondary radio network identifier for a high speed downlink shared channel (H-RNTI), which is a pre-allocated base station to user equipment. Such pre-allocation may be performed by the base station for other purposes, or may be communicated to user equipment for that specific purpose. It should be appreciated that such specific notification of such secondary H-RNTIs provides the base station with greater control over the assignment of these common identifiers. Accordingly, it can be seen that by modifying the control field with a cyclic redundancy code using an identifier common to the user equipment in a separate group, only those user equipments in this group that have this identifier will be able to correctly control the cyclic redundancy code, and so Perform the requested reconfiguration. Typically, each user equipment may first try to perform a cyclic redundancy check using its unique identifier, and if that fails, it can try to perform a cyclic redundancy check using its common identifier. All user equipment belonging to other groups will either assume that this message is not intended for this user equipment or assume that this message is corrupted. In both cases, all other user equipment will not perform the requested reconfiguration.

In one embodiment, the step of encoding the indication comprises: adding a modified header field to the HS-SCCH command, where the modified header field encodes an identifier common to a group of user equipments. Accordingly, the HS-SCCH command header field may be modified to encode an identifier common to a group of user equipments. In other words, the modified header may indicate that this command is a multicast command intended for a group of user equipment. The user equipment may then, in turn, apply the modified processing to such a multicast command to determine whether this message is intended for this user equipment. Therefore, when the user equipment receives the HS-SCCH command with the modified header, only the user equipment having the secondary H-RNTI indicated by this header will attempt to decode this message. All other user equipment will ignore this message. It will be appreciated that the header may be encoded by the H-RNTI itself or may be encoded by an indicator that indicates, usually with fewer bits, the group identifier of the group of user equipment to which it belongs. It will be appreciated that both the base station and the user equipment will be suitable for deriving a group identifier from a secondary H-RNTI.

In one embodiment, the step of encoding the indication comprises: adding a modified header field to the HS-SCCH command, wherein the modified header field encodes an indicator that this HS-SCCH command is for a group of user equipments. Accordingly, the modified header may indicate that this HS-SCCH command is a modified command for a group of user equipments.

In one embodiment, the step of encoding the indication comprises: adding a modified header field to the HS-SCCH command, wherein the modified header field encodes a group indicator, which is an identifier common to a group of user equipments.

In one embodiment, the method comprises the steps of: determining the number of user equipments supported by the base station requiring a general reconfiguration of the radio interface, and encoding and transmitting a plurality of HS-SCCH commands, each of the plurality of HS-SCCH commands being received by a corresponding group of user equipments having a size smaller than a predefined maximum. The problem with transmitting HS-SCCH commands to a group of user equipments is that each of these user equipments will respond with an acknowledgment that a general reconfiguration has occurred, and these acknowledgment messages may overload the base station. In order to reduce the number of such acknowledgments transmitted at any time, many HS-SCCH commands are transmitted in groups of a suitable size. Accordingly, the number of user equipments for which reconfiguration is required is determined. If the number of user equipments is greater than the predetermined threshold value, then a plurality of HS-SCCH commands can be encoded and transmitted, each of which affects the number of user equipments smaller than the threshold value. Thus, the number of received acknowledgment messages can be limited to a number less than a predetermined value in order to reduce the load on the communication network and the base station.

In one embodiment, the transmitting step comprises transmitting at least one of a plurality of HS-SCCH commands at a point in time that is different from at least one of a plurality of HS-SCCH commands. Therefore, by transmitting HS-SCCH commands at different times, acknowledgment messages will likewise be more dispersed, thereby reducing peak load on the communication network and the base station.

In one embodiment, the transmitting step comprises at least one of: transmitting an HS-SCCH command with a power level set for that user equipment in a group that has the lowest signal reception and transmitting an HS-SCCH command on a plurality of carriers. Accordingly, by transmitting the HS-SCCH command with the power level set for the user equipment having the greatest degree of signal attenuation, you can be sure that the HS-SCCH command is received by this user equipment and all other user equipment in the group. Similarly, by transmitting an HS-SCCH command on each of the carriers, the likelihood that this command will be received by each user equipment increases. Also in embodiments, a command sent on different carriers may be software integrated by the user equipment.

In one embodiment, the method comprises the step of: tracking acknowledgment messages from each of a group of user equipments; and at least one of retransmitting the HS-SCCH command and transmitting at least one HS-SCCH command, each HS-SCCH command being encoded for one of a group of user equipment that did not transmit an acknowledgment message. Accordingly, the base station can track acknowledgment messages received from each user equipment, indicating that the requested reconfiguration has been received. After a predetermined period, the base station can then determine whether to retransmit the HS-SCCH command to a group of user equipments or transmit individual messages to those user equipments that have not acknowledged the previous HS-SCCH command.

According to a second aspect, there is provided a base station configured to request a general reconfiguration of a radio interface to be made by each of a group of user equipments from a plurality of user equipments supported by this base station, the base station comprising: a determining logic configured to determine a general reconfiguration of the radio interface, which should be done by each of the user equipment group; coding logic configured to encode the general reconfiguration of the radio interface in the payload field of the HS-SCCH command and encode, in this HS-SCCH command, an indication associating this HS-SCCH command with a group of user equipments; and transmitting logic configured to transmit the HS-SCCH command to a plurality of user equipments supported by the base station.

In one embodiment, a group of user equipments is in a dedicated channel state for a cell (Cell_DCH), and a general reconfiguration of the radio interface comprises at least one of activating at least one carrier, deactivating at least one carrier, primary carrier changes, serving cell changes, switching between normal transmission and intermittent transmission, and switching between normal reception and intermittent reception.

In one embodiment, the coding logic is configured to add a modified cyclic redundancy check field to the HS-SCCH command, wherein the modified cyclic redundancy check field is derived from at least one field of the HS-SCCH command, and the identifier is common to groups of user equipment.

In one embodiment, the coding logic is configured to add a modified header field to an HS-SCCH command, wherein the modified header field encodes an identifier common to a group of user equipments.

In one embodiment, the coding logic is configured to add a modified header field to the HS-SCCH command, wherein the modified header field encodes an identifier indicating that this HS-SCCH command is for a group of user equipments.

In one embodiment, the coding logic is configured to add a modified header field to the HS-SCCH command, wherein the modified header field encodes a group identifier that is an identifier common to a group of user equipments.

In one embodiment, the determining logic is configured to determine the number of user equipments served by the base station requiring a general reconfiguration of the radio interface, and the coding logic and transmitting logic are configured to encode and transmit multiple HS-SCCH commands, each of which is multiple HS- SCCH is received by an appropriate group of user equipment having a size smaller than a predetermined maximum.

In one embodiment, the transmit logic is configured to perform at least one of: transmitting an HS-SCCH command with a power level set for that user equipment in the group that has the lowest signal reception level, and transmitting the HS-SCCH command on many carriers.

In one embodiment, the transmit logic is configured to transmit at least one of a plurality of HS-SCCH commands at a point in time that is different from at least one of a plurality of HS-SCCH commands.

In one embodiment, the base station comprises tracking logic configured to track acknowledgment messages from each of a group of user equipments, and coding logic and transmitting logic are configured to perform at least one of: retransmitting the HS-SCCH command and transmitting multiple HS-SCCH commands, each of the multiple HS-SCCH commands being encoded for one of a group of user equipment that has not transmitted an acknowledgment message.

According to a third aspect, there is provided a method for performing a general reconfiguration of a radio interface in a user equipment in response to a request from a supporting base station, the method comprising the steps of: receiving an HS-SCCH command from a base station; decoding the indication in the HS-SCCH command associating the HS-SCCH command with a group of user equipments; determining whether this indication matches the group with which the user equipment is associated; and if a match occurs, decoding the general reconfiguration of the air interface in this HS-SCCH command and performing this general reconfiguration of the air interface.

In one embodiment, the user equipment is in a dedicated channel state for the cell (Cell_DCH), and the general reconfiguration of the radio interface comprises at least one of: activating at least one carrier, deactivating at least one carrier, primary carrier changes, serving cell changes, switching between normal transmission and intermittent transmission, and switching between normal reception and intermittent reception.

In one embodiment, the decoding and determining step comprises extracting the cyclic redundancy check field from the HS-SCCH command and performing cyclic redundancy check using an identifier common to this group of user equipments. Accordingly, if the regular cyclic redundancy check by the received HS-SCCH command, performed by the user equipment using its unique H-RNTI, fails, the user equipment can then perform the cyclic redundancy check using the common identifier. If the cyclic redundancy check code using the common identifier shows a positive result, then the user equipment can perform the requested reconfiguration.

In one embodiment, the decoding and determining step comprises identifying an indication in the header field of an HS-SCCH command indicating a group of user equipments to which this HS-SCCH command corresponds. Therefore, determining that this HS-SCCH command corresponds to a group of user equipments can be determined directly from the header field.

In one embodiment, the decoding and determining step comprises identifying an indicator in the header field of the HS-SCCH command indicating that this HS-SCCH command corresponds to a group of user equipments, extracting the cyclic redundancy check field from this HS-SCCH command and performing cyclic control redundant code using an identifier common to this group of user equipments. Accordingly, if the user equipment determines from the header field that this HS-SCCH command is for a group of user equipment, then the user equipment can first perform a cyclic redundancy check using a common identifier, thereby avoiding the need for a first cyclic redundancy check using its unique H-RNTI.

In one embodiment, the method comprises the step of: sending an acknowledgment to the base station with a temporal offset depending on at least one of: random offset, fixed offset and offset derived from the unique identifier. Thus, acknowledgment messages from user equipment can be spaced in time, thereby preventing the base station from being overloaded.

According to a fourth aspect, user equipment is provided configured to perform a general reconfiguration of a radio interface in response to a request from a supporting base station, the user equipment comprising: receiving logic configured to receive an HS-SCCH command from a base station; decoding logic configured to decode an indication in the HS-SCCH command associating this HS-SCCH command with a group of user equipments; defining logic, configured to determine if this indication matches the group with which the user equipment is associated; and reconfiguring logic, configured to, in response to the indication from the determining logic that a match has occurred, decode the general reconfiguration of the radio interface to the HS-SCCH command and perform this general reconfiguration of the radio interface.

In one embodiment, the user equipment is in a dedicated channel state for the cell (Cell_DCH), and the general reconfiguration of the radio interface comprises at least one of: activating at least one carrier, deactivating at least one carrier, primary carrier changes, serving cell changes, switching between normal transmission and intermittent transmission, and switching between normal reception and intermittent reception.

In one embodiment, the decoding logic and the determining logic are configured to extract the cyclic redundancy check field from the HS-SCCH command and perform cyclic redundancy check using an identifier common to a group of user equipments.

In one embodiment, the decoding logic and the determining logic are configured to identify an indication of an HS-SCCH command in the header field indicating a group of user equipments with which this HS-SCCH command is associated.

In one embodiment, the decoding logic and the determining logic are configured to identify an indicator in the header field of the HS-SCCH command, indicating that this HS-SCCH command corresponds to a group of user equipments, retrieve the cyclic redundancy check field from the HS-SCCH command, and execute cyclic redundancy check using an identifier common to a group of user equipment.

In one embodiment, the user equipment comprises transmit logic configured to send an acknowledgment to the base station with a time offset depending on at least one of: random offset, fixed offset, and offset derived from the unique identifier.

According to a fifth aspect, a computer program product is provided configured to, when executed on a computer, perform the steps of the method of the first aspect.

According to a sixth aspect, there is provided a computer program product configured to, when executed on a computer, perform the steps of the method of the third aspect.

Additional specific and preferred aspects are set forth in the attached independent and dependent claims. The features of the dependent claims may be combined with the features of the independent claims, if necessary, and in combinations other than those expressly set forth in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be further described with reference to the accompanying drawings, in which:

Figure 1 illustrates a wireless communication system 10 in one embodiment;

Figure 2 illustrates the overall operation of user equipment upon receipt of an HS-SCCH command;

Figure 3 illustrates cyclic redundancy check of an HS-SCCH command; and

4 illustrates the transmission of HS-SCCH commands and HS-DPCCH acknowledgments between a base station and user equipments.

DETAILED DESCRIPTION

Figure 1 illustrates a wireless communication system 10 in one embodiment. User equipment 50 moves through a wireless communication system. Base stations 20 are provided that support radio coverage areas 30. A number of such base stations 20 are provided and geographically distributed to provide a wide coverage area to user equipment 50. When the user equipment is in the area served by base station 30, communication can be established between the user equipment and this base station through corresponding radio channels. Each base station typically supports a number of sectors in a geographic service area 30.

Typically, different antennas in a base station support each respective sector. Accordingly, each base station 20 has multiple antennas and signals sent through different antennas are evaluated electronically to provide a sectorized approach. Of course, it should be appreciated that Figure 1 illustrates a small subset of the total number of user equipment and base stations that may exist in a conventional communication system.

The wireless communication network of the wireless communication network is controlled by a radio network controller (RNC) 40. The radio network controller 40 controls the operation of the wireless communication system by communicating with a plurality of base stations via the return link 60. The radio network controller also communicates with user equipment 50 through each base station.

The radio network controller 40 contains a list of neighbors that includes information on the geographical relationship between sectors supported by the base station 20. In addition, the radio network controller 40 contains location information that provides information about the location of the user equipment 50 in the wireless communication network 10. The radio network controller is configured to route traffic through circuit-switched and packet-switched networks. Therefore, a mobile switching center is provided with which the radio network controller can communicate. The mobile switching center can communicate with a circuit-switched network such as a public switched telephone network (PSTN) 70. Similarly, a network controller can communicate with a public packet radio service (SGSN) service support node and a packet radio gateway support node. General Use (GGSN). GGSN can communicate with packet core networks, such as, for example, the Internet.

User equipment 50 typically transmits information and data to base station 20 so that it can be redirected to a wireless communication network. The user equipment may, for example, need to transmit data to the base station, then to send text messages, voice information when the user uses this equipment to make a phone call, or other data. The base station 20, in combination with the parameters set by the radio network controller 40, allocates resources to the user equipment in a manner aimed at optimizing the operation of the wireless communication network 10.

In the universal mobile communication system (UMTS), a multi-cell high-speed downlink packet access (MC-HSDPA) arrangement is provided. In MC-HSDPA, a sector is defined as the geographical coverage area of a base station or Node B. A sector can consist of several cells, where each cell aims to cover the same coverage area as a sector, and uses separate frequency carriers for its transmissions. A frequency carrier may be within the same frequency range or distributed over two frequency ranges. MC-HSDPA is an extension of Dual Cell High Speed Downlink Packet Access (DC-HSDPA). In MC-HSDPA, user equipment can receive up to four simultaneous downlink transmissions from four different cells. Accordingly, the MC-HSDPA can potentially double and quadruple the bandwidth of the downlink DC-HSDPA and (single-cell) HSDPA, respectively. MC-HSDPA is also sometimes referred to as 4C-HSDPA (four-cell HSDPA) or 3C-HSDPA, when the user equipment receives simultaneously transmissions from four or three cells, respectively.

In a multi-carrier system, each carrier will have independent downlink radio links from the base station to the user equipment. These downlink radio links are independently controlled, since each carrier will likely have different propagation paths to the user equipment. For HSDPA systems capable of multi-carrier operation, more than two downlink carriers may be provided. It will be appreciated that in a multi-carrier network, the number of downlink carriers may not coincide with the number of uplink carriers. Furthermore, the intended number of downlink carriers may not necessarily be a doubling of the number of provided uplink carriers. In multi-carrier HSDPA mode, each sector served by a base station may have several carrier frequencies or “carriers” associated with it. A carrier or cell supported by a carrier covers the same geographical region as the sector. Each cell is served by different carrier frequencies. Thus, it should be understood that in a single carrier system, a cell is equivalent to a sector since the sector has only one cell or carrier frequency. Nevertheless, in a multi-carrier network, each sector can contain several cells, each cell is served simultaneously by a different carrier frequency.

The user equipment may be in standby mode or in a radio resource management (RRC) connected mode. The Cell_DCH mode is one of the states in a radio resource control connected state in which user equipment can transmit and receive a large amount of data. The MC-HSDPA function operates in the Cell_DCH state, in which state the user equipment and the Node B (Node B) support physical layer synchronization in the downlink and uplink. The HS-DSCH Radio Network Transmission Identifier (H-RNTI) is a unique identifier for user equipment running in HSDPA, and it is unique for each user equipment in the Cell_DCH state.

Additionally allocate a secondary H-RNTI, which is common to all or a group of user equipment supported by the base station. The secondary H-RNTI used in the enhanced Cell_FACH and Cell_PCH states to send common control signals via the HS-DSCH can be used for this purpose; this set of secondary H-RNTIs is broadcast in the system information broadcast (SIB) 5 and 5bis. Alternatively, a set of secondary H-RNTIs may be specifically allocated by the base station for this purpose. Specific allocation of secondary H-RNTIs provides the base station with greater control over group size limits to reduce the number of concurrent acknowledgment messages generated by user equipment, as will be described in more detail below.

In MC-HSDPA, the primary carrier is a cell that carries the main control channels and cannot be deactivated. There is only one primary carrier and the other cells are called secondary carriers (for example, Secondary Carrier 1, Secondary Carrier 2 and Secondary Carrier 3). The user equipment will announce a radio link failure if the primary carrier radio link fails, even if the secondary carriers work fine (for example, if they are lightly loaded or have a better radio channel). Secondary carriers provide the natural redundancy of the radio link, but these redundancies cannot be used.

Carrier management can be performed using the HS-SCCH (High Speed Shared Control Channel) command. The HS-SCCH command is a level 1 signaling from the supporting base station to the user equipment, which allows you to make quick commands / orders. In addition to deactivating / activating secondary carriers, HS-SCCH commands can also be used to enable discontinuous transmission and reception.

Embodiments provide a technique for quickly reconfiguring a large number of user equipments using a modified HS-SCCH command. For example, there are scenarios where the base station needs to deactivate or activate a large group of user equipment in a cell. For example, it is useful if the base station can deactivate a separate secondary carrier for a group or all user equipments for interference control or energy saving. In power saving mode, the base station may wish to turn off one of its carriers due to low traffic conditions and thus deactivate secondary carriers for all user equipments in the cell, as will be described in more detail below.

Figure 2 illustrates the overall operation of user equipment upon receipt of an HS-SCCH command. In the example shown in Figure 2, the HS-SCCH command contains the information required to decode the corresponding high-speed downlink shared channel (HS-DSCH) or contains a command for user equipment. When the HS-SCCH command is sent, it is sent ahead of the two slots, as shown in Figure 2, where the first slot contains information such that the user equipment can start decoding the HS-DSCH two slots later. Thus, this gives one slot (slot 2) to the user equipment to reconfigure itself.

As shown in Figure 2, the HS-SCCH 105 command contains three main fields (other fields were omitted to improve clarity). These three main fields are the header field 100, the payload field 110, and the cyclic redundancy check field 120. Cyclic redundancy check applies to HS-SCCH commands for detecting errors on user equipment and is usually masked using H-RNTI, unique to user equipment, in order to ensure that only the cyclic redundancy check performed by this user equipment passes.

As shown in Figure 2, at least three different modified views of the HS-SCCH command 105A-105C can be transmitted by the base station, these modified views of the HS-SCCH command can be considered as broadcast or multicast commands, since they are designed to receive more than one user equipment. A similar unicast view of these commands can be used for those user equipments that have not acknowledged the multicast command, as will be described in more detail below.

In a first form, HS-SCCH commands 105A use a standard header field 100, together with a six-bit command field 110A, encoding the general reconfiguration to be done by the user equipment in the specified group. The cyclic redundancy check field 120A includes conventional cyclic redundancy check (16 bits), which is then masked by a secondary H-RNTI (16 bits) common to all user equipments in this group, as shown in Figure 3.

In the second form of the HS-SCCH command 105B, this header is a modified header 100B, which indicates that this HS-SCCH command is a modified HS-SCCH command, intended to be received by a group of user equipments. The modified header field 100B also includes an indication of the group for which this command is intended. Typically, the group indicator will be an encoded representation of the secondary H-RNTI output by both the base station and user equipment from this common H-RNTI. Again, this command is the same as the one mentioned above, while cyclic redundancy check is the standard cyclic redundancy check without any masking based on H-RNTI.

In a third form, HS-SCCH commands 105C use an additionally modified header field 100C, which indicates that this message is an HS-SCCH command. The command field 110A is identical to the two messages described above, while the cyclic redundancy check field 120A includes a cyclic redundancy check masked by a secondary H-RNTI.

Therefore, with the first view of the HS-SCCH command 105A, the user equipment for receiving this message will perform standard processing of the HS-SCCH command using its unique H-RNTI, as shown in Figure 3. Masked CRC and H-RNTI are removed from the control field 120A cyclic redundancy code and unmasked using a unique H-RNTI to extract cyclic redundancy check bits. The cyclic redundancy check bits are then decoded to detect errors. An error will occur if this HS-SCCH is not intended for user equipment, since another unique H-RNTI intended for other user equipment (i.e., target user equipment) was used at the base station to mask cyclic redundancy check control. It is also possible that this HS-SCCH will not be able to pass cyclic redundancy check, even if the correct H-RNTI has been used, due to real errors in the HS-SCCH command. The user will reject any HS-SCCH commands that have not passed cyclic redundancy check decoding because they contain errors. However, if cyclic redundancy check fails, instead of just stopping processing, the user equipment will then re-run the cyclic redundancy check using a secondary H-RNTI. If cyclic redundancy check passes, then the user equipment will decode the instruction field 110A using modified decoding for HS-SCCH multicast instructions. It should be appreciated that any suitable coding technique may be used to encode the required information for reconfiguring the radio interface mentioned above.

However, it should be appreciated that the problem with decoding the first kind of HS-SCCH instruction 105A is that the cyclic redundancy check needs to be performed twice. Accordingly, in the second form of the HS-SCCH command 105B, the configuration of the header field 100B indicates that this message is an HS-SCCH multicast command, and provides an indication of the group for which this command is intended. Provided that the indication matches the group to which this user equipment belongs, the user equipment will perform cyclic redundancy check without using its unique H-RNTI. Provided that the cyclic redundancy check has passed, the user equipment will decode the command field and apply the requested reconfiguration.

Similarly, with a third kind of HS-SCCH command 105C, the user equipment is able to output from the modified header field 100C that this message is an HS-SCCH multicast command and will directly perform cyclic redundancy check using its secondary H-RNTI. This eliminates the need for cyclic redundancy check using the unique H-RNTI first, and speeds up the process. Provided that the cyclic redundancy check has passed, the user equipment will decode the command field and apply the requested reconfiguration.

The base station will attempt to transmit 105A-105C HS-SCCH commands with sufficiently high power so that they reach all user equipments in the group. The HS-SCCC command can be transmitted with the maximum possible power or with the power to reach the user equipment with the worst radio conditions (that is, to reach the user equipment that is the most distant or that has the highest level of signal attenuation). The reliability of HS-SCCH commands 105A-105C can be further improved by transmitting over all configured carriers. Received HS-SCCH commands from different carriers can then be gently combined at the baseband level in user equipment. Therefore, those user equipments that have more than one active carrier will receive additional reliability by receiving the same HS-SCCH command on more than one carrier.

In the CELL_DCH state, the HS-SCCH command is acknowledged by user equipment using a high speed dedicated physical control channel (HS-DPCCH) as a feedback channel. Accordingly, an HS-SCCH command sent to a large group of user equipment can initiate a large number of simultaneous acknowledgment transmissions via the HS-DPCCH. This may cause overload or interference at the base station. Thus, to reduce the number of acknowledgments received by the base station at any time, HS-SCCH commands are transmitted to different groups of user equipment at different points in time so that the response from each group arrives at the base station at different points in time. The size of each group is selected so that the base station can handle possible simultaneous acknowledgments from these user equipments and this size is controlled by controlling the allocation of secondary H-RNTIs. Consider an example 4C-HSDPA sector that contains 40 user equipments with all four active carriers. The carriers are named as C1, C2, C3 and C4. C1 is the primary carrier, and thus cannot be deactivated. There are four secondary H-RNTIs dedicated to limit the size of each group to no more than ten user equipments. User equipments are allocated and secondary H-RNTIs are allocated as follows.

UE H-RNTI Highlighted Secondary 1 to 10
11 to 20
21 to 30
31 to 40 1001 to 1010
2001 to 2010
3001 to 3010
4001 to 4010 10,000
20000
30000
40,000

Now suppose that the carriers C1 and C4 are overloaded. The base station decides to deactivate the C2 carrier for half of the user equipment and deactivate the C4 carrier for the remaining half of the user equipment, as described below.

UE Carriers for deactivation 1 to 10 C2 11 to 20 C2 21 to 30 C4 31 to 40 C4

Thus, the base station sends four separate multicast HS-SCCH commands with the following configuration:

HS-SCCH Team Carriers for deactivation Secondary H-RNTI Target UE HS-SCCH 1 C2 10,000 1 to 10 HS-SCCH 2 C2 20000 11 to 20 HS-SCCH 3 C4 30000 21 to 30 HS-SCCH 4 C4 40,000 31 to 40

To avoid receiving a large number of simultaneous HS-DPCCH acknowledgment messages, the base station sends the HS-SCCH 1 command and the HS-SCCH 3 command together, and then, at five time slots, sends the HS-SCCH 2 command and the HS-SCCH 4 command together. This is shown in more detail in Figure 4.

In order to further reduce the number of simultaneous HS-DPCCH acknowledgment transmissions from user equipments, each user equipment in a group can send its own HS-DPCCH acknowledgment at different times. Accordingly, each user equipment can send its acknowledgment to the HS-DPCCH based on a random variable, a fluctuating quantity, a predetermined offset, or based on a user equipment identifier. In one embodiment, the offset is determined based on the isolated H-RNTI, as follows:

HS-DPCCH_TTI = Dedicated H-RNTI MOD K,

where HS-DPCCH_TTI is a delay amount in transmission time intervals before sending an HS-DPCCH acknowledgment; and K is the number provided by the base station (the larger the number, the longer it will take for all acknowledgments to reach the base station, and thus, this number should balance between the need to delay the receipt of all acknowledgments and the number of simultaneous acknowledgments that the base station can process) .

In the example mentioned above, there are two HS-SCCH multicast commands sent to 20 user equipment in each attempt. Acknowledgment of HS-DPCCH from 20 user equipments at the same time may still not be valid at the base station. To further reduce the number of simultaneous acknowledgments, acknowledgment HS-DPCCHs are sent at different times using the above formula, where K = 5. Using this arrangement, the number of transmission time slots for the delay before sending HS-DPCCH acknowledgments for user equipments 1-10 is shown below.

UE Dedicated H-RNTI TTI number for delay one 1001 one 2 1002 2 3 1003 3 four 1004 four 5 1005 0 6 1006 one 7 1007 2 8 1008 3 9 1009 four 10 1010 0

In this example, user equipments 5 and 10 will send an acknowledgment to the HS-DPCCH immediately, followed by user equipments 1 and 6 one transmission time later. A similar calculation can be performed for other groups of user equipment. Thus, the base station receives only four HS-DPCCH handshakes at once, as shown in more detail in Figure 4.

As soon as the user equipment sends an acknowledgment to the HS-DPCCH, the user equipment can execute the command and reconfigure its radio interface.

The base station will track acknowledgments from each user equipment. For those user equipments that miss the HS-SCCH multicast command (which will be determined by the lack of acknowledgment at the base station), the base station can resend the allocated HS-SCCH command to the specific user equipment (if the number of user equipments that refused to acknowledge is small) or repeatedly send the HS-SCCH multicast command (if the number of user equipment that refused to acknowledge is large).

In this example, the user equipment 27 was not able to decode the HS-SCCH 3 command and, accordingly, did not accept this command. Since only one user equipment was not able to receive the command, the base station sends a targeted HS-SCCH command to the user equipment to deactivate the C4 carrier. In a second attempt, user equipment 27 receives this command and sends an acknowledgment back through the HS-DPCCH feedback channel.

Accordingly, it can be seen that instead of having to transmit 40 individual HS-SCCH commands to reconfigure user equipments, only four HS-SCCH multicast commands need to be transmitted.

As a result, a technique is provided in which a base station can send an HS-SCCH command to a group of user equipment instead of sending individual commands to each user equipment. This reduces the number of commands needed to reconfigure a group of user equipment. This is especially applicable when the base station needs to activate or deactivate carriers for a group of user equipment, for example, in order to balance the load or save energy.

One skilled in the art will readily recognize that the steps of the various methods described above can be performed by programmed computers. Herein, some embodiments are also intended to encompass program storage devices, such as digital data storage devices, which are computer readable or computer readable and encode machine-executable or computer-executable instruction programs, where said instructions execute some or all of the steps of the above methods. Program storage devices may be, for example, digital storage devices, magnetic storage media such as magnetic disks and magnetic tapes, hard disk drives, or optically readable digital storage media. Embodiments are also intended to encompass computers programmed to perform the steps of the above methods.

The functionality of the various elements shown in the drawings, including any function blocks labeled “processors” or “logic,” can be provided using specialized hardware, as well as hardware configured to execute the software in conjunction with the corresponding software . Once provided by the processor, the functionality may be provided by a single specialized processor, a single shared processor, or a plurality of individual processors, some of which may be shared. Moreover, the explicit use of the terms “processor”, “controller”, “logic” should not be construed as referring exclusively to hardware configured to execute software, and may indirectly include, without limitation, processor hardware for digital signal processing (DSP), network processor, specialized integrated circuit (ASIC), user-programmable logic array (FPGA), read-only memory (ROM) for storing software echeniya, random access memory (RAM) and nonvolatile memory. Other hardware, conventional and / or special, may also be used. Similarly, any switching devices shown in the drawings are only schematic. Their functionality can be implemented through the operation of program logic, through specialized logic, through the interaction of a control program and specialized logic, or even manually, a specific execution method is chosen by the designer, as is more clear from the context.

Specialists in the art should understand that any functional diagrams in this document are conceptual representations of an explanatory diagram that implements the principles of this invention. Similarly, it should be appreciated that any flowcharts, function diagrams, state transition diagrams, pseudo-code, and the like are various processes that can be essentially represented on a computer-readable medium, and thus executed by a computer or processor, whether or not the computer or processor is explicitly shown.

The description and drawings merely illustrate the principles of the present invention. Thus, those skilled in the art should be able to develop various schemes that, although not described or shown explicitly in this document, embody the principles of this invention and are included in its essence and scope. Moreover, all the examples set forth in this document are mainly intended specifically for educational purposes only, to help the reader understand the principles of this invention and the concepts presented by the inventor (s) for the development of this technical field, and should be construed as not limited to specifically set forth examples and conditions. In addition, all statements herein, setting forth principles, aspects, and embodiments of the present invention, as well as specific examples thereof, are intended to encompass equivalents thereof.

Claims (15)

1. A method for requesting a general reconfiguration of a radio interface to be made by each of a group of user equipments from a plurality of user equipments supported by a base station in a multi-carrier wireless communication system, the method comprising the steps of:
determining said general reconfiguration of the radio interface to be done by each of said group of user equipments;
encoding said general reconfiguration of the radio interface in a payload field of a high speed shared control channel (HS-SCCH) command;
encode, in said HS-SCCH command, an indication associating said HS-SCCH command with said group of user equipments; and
transmitting said HS-SCCH command to said plurality of user equipments supported by said base page. 2. The method of claim 1, wherein said group of user equipments is in a dedicated channel state for a cell (Cell_DCH), and said general reconfiguration of the radio interface comprises at least one of: activating at least one carrier, deactivating at least one carrier , primary carrier changes, serving cell changes, changes between normal transmission and intermittent transmission, and changes between normal reception and intermittent reception. 3. The method of claim 1, wherein said encoding step of said indication comprises a step in which:
add the modified cyclic redundancy check field to said HS-SCCH command, said modified cyclic redundancy check field being derived from at least one field of said HS-SCCH command and an identifier common to said group of user equipments. 4. The method of claim 1, wherein said encoding step of said indication comprises a step in which:
adding a modified header field to said HS-SCCH command, wherein said modified header field encodes an identifier common to said group of user equipments. 5. The method of claim 1, wherein said encoding step of said indication comprises a step in which:
adding a modified header field to said HS-SCCH command, wherein said modified header field encodes an indicator that said HS-SCCH command is for a group of user equipments. 6. The method according to any one of paragraphs. 1-5, wherein said encoding step of said indication comprises a step in which:
adding a modified header field to said HS-SCCH command, wherein said modified header field encodes a group indicator representing an identifier common to said group of user equipments. 7. The method according to any one of paragraphs. 1-5, containing stages in which:
determining the number of user equipments supported by said base station requiring said general reconfiguration of the radio interface, and encoding and transmitting a plurality of said HS-SCCH commands, each of said plurality of said HS-SCCH commands being received by a corresponding group of user equipments having a size smaller than a predetermined maximum. 8. The method according to any one of paragraphs. 1-5, in which said transfer step comprises:
at least one of the steps of transmitting said HS-SCCH command with a power level set for that user equipment in said group that has a lower signal reception level, and transmitting said HS-SCCH command on a plurality of carriers. 9. The method according to any one of paragraphs. 1-5, containing the stage on which:
tracking acknowledgment messages from each of said group of user equipments; and
at least one of the steps of retransmitting said HS-SCCH command and transmitting a plurality of HS-SCCH commands, each of said plurality of HS-SCCH commands being encoded for one of said group of user equipment that has not transmitted an acknowledgment message. 10. A base station configured to request a general reconfiguration of a radio interface to be made by each of a group of user equipments from a plurality of user equipments supported by said base station, the base station comprising:
determining logic configured to determine said general reconfiguration of the radio interface to be made by each of said group of user equipments;
coding logic configured to encode said general reconfiguration of the radio interface in the payload field of the HS-SCCH command and encode, in said HS-SCCH command, an indication associating said HS-SCCH command with said group of user equipments; and
transmitting logic configured to transmit said HS-SCCH command to said plurality of user equipments supported by said base station. 11. A method for performing a general reconfiguration of a radio interface in a user equipment in response to a request from a supporting base station, the method comprising the steps of:
receiving an HS-SCCH command from said base station;
decoding the indication in said HS-SCCH command associating said HS-SCCH command with a group of user equipments;
determining whether said indication matches the group with which said user equipment is associated; and
if a match occurs, said general reconfiguration of the radio interface is decoded in said HS-SCCH command and said general reconfiguration of the radio interface is performed. 12. The method of claim 11, wherein said decoding and determining step comprises the steps of: extracting a cyclic redundancy check field from said HS-SCCH command and performing a cyclic redundancy check using an identifier common to said group of user equipments. 13. The method of claim 11 or 12, wherein said decoding and determining step comprises: identifying said indication in a header field of said HS-SCCH command indicating a group of user equipments with which said HS-SCCH command is associated. 14. The method according to any one of paragraphs. 11-12, wherein said decoding and determining step comprises the steps of identifying an indicator in a header field of said HS-SCCH command indicating that said HS-SCCH command is associated with a group of user equipments, extracting a cyclic redundancy check field from said command HS-SCCH and perform cyclic redundancy check using an identifier common to said group of user equipments. 15. Wireless user equipment configured to perform a general reconfiguration of the radio interface in response to receiving a request from a supporting base station, the user equipment comprising:
receiving logic configured to receive an HS-SCCH command from said base station;
decoding logic configured to decode an indication in said HS-SCCH command associating said HS-SCCH command with a group of user equipments;
defining logic configured to determine whether said indication matches a group with which said user equipment is associated; and
reconfiguring logic configured to, in response to an indication from said determining logic that a match has occurred, decode said general reconfiguration of the radio interface in said HS-SCCH command and perform said general reconfiguration of the radio interface.

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