GB2509969A

GB2509969A - Scheduling communications on a carrier in a multi-carrier communications network to avoid interruption by a measurement on another carrier

Info

Publication number: GB2509969A
Application number: GB1301014.5A
Authority: GB
Inventors: Christopher Peter Callender; Keiichi Kubota
Original assignee: Broadcom Corp
Current assignee: Broadcom International Ltd; Broadcom Corp
Priority date: 2013-01-21
Filing date: 2013-01-21
Publication date: 2014-07-23
Also published as: GB201301014D0

Abstract

Scheduling communications in a multi-carrier communications network wherein a user equipment 102 is capable of communicating with a network node 104 via a plurality of carriers, and whereby reception of communications occur over at least one carrier of a first type, for which reception of communications is configured but has been indicated by the network node 104 to be inactive at the user equipment 102, and at least one carrier of a second type, for which the user equipment 102 is currently configured to receive communications. A carrier of the second type for which reception of communications, by the user equipment 102, would be interrupted by an intended. measurement of a characteristic of the carrier of the first type is determined, and the scheduling of communications on the or each said carrier of the second type is selectively modified responsive to the determination.

Description

A METHOD. APPARATUS AND COMPUTER PROGRAM FOR CONTROLLiNG

COMMUNICATIONS IN A COMMUNICATIONS NETWORK

Technical Field

Embodiments relate to a method, apparatus and computer program for controlling communications in a communications network, and are particularly, but not exclusively, suitable for scheduling communications utilising a plurality of carriers.

Background

Wireless networks have in recent years experienced a considerable increase in the amount of data being transmitted to and from wirelessly connected devices or user equipment. This increase in traffic has been mainly due to the rapid and widespread uptake of smart phones, the availability of mobile broadband dongles for computers and affordable rates for consumers. In order to increase the peak data rates per user and make better use of the available network resources, it has been proposed to use two or more carriers (in the downlink direction or uplink direction or both) and1or two or more frequencies or bands (again, in the downlink direction or uplink direction or both) and/or two or more data flows (again, in the downlink direction or uplink direction or both). In simple terms, by using two or more carriers in "carrier aggregation", a wireless device connects wirelessly using two or more network carriers to increase the peak data rates available and to make better use of the available resources by multiplexing the carriers, and achieves greater spectrum efficiency through joint resource allocation and balancing loads among the downlink andi'or uplink carriers. In general, the carriers may be in different but overlapping cells, may use the same or different frequencies, and may or may not use MIMO (multiple-input and multiple-output, i.e. the use of multiple antennas at both the transmitter and receiver to improve communication performance). Similar benefits are achieved with multiflow operation. These proposals for multi-carrier and/or multi-band and/or multiflow transmissions have application to many network transmission protocols, including wirclcss nctwork transmission protocols in particular.

As a particular example, 3GPP (3rd Generation Partnership Project) defines a HSPA (High Speed Packet Access) protocol which uses a combination of high-speed downlink packet acccss (HSDPA) and enhanced dedicated channel (E-DCFI). FISPA increases available data rates and also boosts capacity in UNTS networks and provides significant latency reductions. In 3GPP Release-S and Release-9, the dual ceH HSDPA (DC-HSDPA) and dual band DC-HSDPA (or DB-DC-HDSPA) features wcrc introduccd. Both thcsc fcaturcs allow a Node B to serve onc or morc users in the downlink direction by simultaneous operation of HSDPA on two different carrier frequencies in two geographically overlapping cells, thus improving the user experience across the entire cell coverage area. Whilst initially it was proposed to use two carricrs or cells and two frcqucncics or bands, rcccnt proposals cxtcnd this to more than two carriers/cells and more than two frequencies/bands (which will generically be referred to herein as multicarrier and multiband respectively). As a particular example, recent proposals in 3GPP provide for the use of up to eight network cells for this purpose (termed 8C-HSDPA or 8-Cell High Speed Downlink Packet Access), which in theory could provide a maximum physical layer throughput or bandwidth of 336 Mbps.

In these different HSDPA architectures, a carrier associated with a user equipment's (UE) serving cell or primary cell is known as a primary carrier. A carrier associated with another cell (i.e. secondary cell) with respect to the liE is known as a secondary carrier. The secondary carriers are either "activated" or "deactivated" according to whether communications are scheduled on the secondary carriers for that liE. An indication to changc thc activation/deactivation status can be signalled from the Node B to the liE via a High Speed Shared Control Channel (HS-SCCH) in a HS-SCCH order. As an example, in the case where a UE has a single-receiver chain for receiving communications on multiple carriers, the deactivation of a secondary carrier in thc downlink can bc signalled by the Nodc B in an HS-SCCI-l ordcr to indicate to the liE that no scheduled communications are planned for that secondary carrier. In response, the liE can reduce or focus its receiver chain bandwidth to exclude the deactivated carrier and focus on the primary downlink carrier in order to improve the downlink performance of the primary downlink carrier and provide a power saving at the liE. In the case of DB-DC-HSDPA, the liE will typically have at least two receiver chains, with each receiver chain being configured to receive communications on one or more carriers. An indication of a deactivation of a secondary carrier can therefore allow the lIE to turn off a receiver chain relating to that deactivated secondary carrier in order to improve the downlink performance of the primary downlink carrier and provide a power saving at the lIE. In each of these cases, the UE may bc requircd to pcrform measurements of the deactivatcd carrier, such as when the UE is mobile and needs to make handover decisions. In order to perform such measurements, the lIE will need to reconfigure its receiver chain, which could cause communications on the active carriers to be interrupted, thereby resulting in undesirable data packet losses at the UE.

Summary

According to an exemplary embodiment, there is provided a method of controlling communications in a communications network, the communications network comprising a network node and a user equipment capable of communicating with the network node via a plurality of carriers, each having a different carrier frequency, wherein communications occur over at least one carrier of a first type, for which reception of communications is configured but has been indicated by the network node to be inactive at the user equipment, and at least one carrier of a second type, for which the user equipment is currently configured to receive communications, the method comprising: determining at least one said carrier of the second type for which reception of scheduled communications, by the user equipment, would be interrupted by an intended measurement of a characteristic of the carrier of the first type by the user equipment; and selectively modifying the scheduling of communications on the or each said carrier of the second type responsive to the determination.

Determining a carrier of the second type (i.e. an active carrier) for which scheduled communications on that carrier would be interrupted by an intended measurement of a carrier of the first type (i.e. a deactivated carrier) allows any deleterious effects of the interruption to be compensated for by, for example, allowing the scheduling of communications on the carrier of the second type to be modified.

Such modification can be used, for example, to avoid any scheduling when the intended measurement is to take place. Therefore, the idcntifying of the active carriers for which reception of scheduled communications would be interrupted, in addition to the modified scheduling, can enable data packet losses at the user equipment as a consequence of the measurement to be reduced or prevented.

According to a ñrthcr excmplary embodiment, there is provided a method of controlling communications in a communications network, the communications network comprising a user equipment capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the network node as to be inactive at the user equipment, and one or more carriers of a second type, for which the user equipment is currently configured to receive communications, the method comprising: responsive to a determination, by the user equipmcnt, that a measurement of a characteristic of the carrier of the first type is intended by the user equipment, determining at least one carrier of the second type, for which reception by the user equipment of scheduled communications would be interrupted by the intended measurement of a characteristic of the carrier of the first type; and generating first data for output to the network node, the first data comprising an identification that the intended measurement would cause an interruption to reception, by the user equipment, of communications on said at least one carrier of the second type.

Enabling a user equipment to determine if a carrier of the second type (i.e. an active carrier) for which scheduled communications on that carrier would be interrupted by an intended measurement of a carrier of the first type (i.e. a deactivated carrier) and generate first data identifying the interruption to the active carrier for output to the network node allows the network node to be told which active carrier would be affected by the measurement. This allows the network node to apply a modification of its scheduling to avoid or reduce data packet losses at the user equipment when such a measurement is to occur.

According to yet a further exemplary embodiment, there is provided a method of configuring a user equipment to measure a network resource in a communications network, the network resource having a carrier frequency and the user equipment being capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the nctwork node as to be inactive at the user equipment, and at least one carrier of a second type, for which the user equipment is currently configured to receive communications, the method comprising: responsive to a determination, by the user equipment, that a measurement of a characteristic of the carrier of the first type is intended by the user equipment, determining a said carrier of the second type, for which reception by the user equipment of scheduled communications would be interrupted by the intended measurement of a characteristic of the carrier of the first type; and selectively configuring the user equipment to use a predetermined scheduling pattern to perform the measurement based on the determination of whether reception of scheduled communications on the carrier of the second type would be interrupted by the intended measurement, the predetermined scheduling pattern having a measurement slot indicating a time period in which communications are not scheduled with the network node on the carrier of the second type.

Therefore a predetermined scheduling pattern can be used by the user equipment to perform a measurement when it is determined that a carrier of the second type would be interrupted by the intended measurement. This allows a specified measurement slot to be used for performing the measurement. For example, knowledge of the specified measurement slot in the network could be used by the network to avoid scheduling communications on the carrier of the second type that would be interrupted by the intended measurement within that measurement slot so as to reduce or avoid data packet losses at the user equipment.

According to a further exemplary embodiment, there is provided a computer program comprising a set of instructions for execution by a computing system capable of communicating with a user equipment via a plurality of carriers, each having a different carrier frequency, wherein communications occur over at least one carrier of a first type, for which reception of communications is configured but has been indicated by the network node to be inactive at the user equipment, and at least one carrier of a second type, for which the user equipment is currently configured to receive communications, in which the set of instructions, when executed by the computing system. cause the computing system to perform the steps of: determining at east one said carrier of the second type for which reception of scheduled communications, by the user equipment, would be interrupted by an intended measurement of a characteristic of the carrier of the first type by the user equipment; and selectively modifying the scheduling of communications on the or each said carrier of the second type responsive to the determination.

According to a further exemplary embodiment, there is provided a computer program comprising a set of instructions for execution by a computing system capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the network node as to be inactive at the computing system, and one or more carriers of a second type, for which the computing system is currently configured to receive communications, in which the set of instructions, when executed by the computing system, cause the computing system to perform the steps of: responsive to a determination, by the computing system, that a measurement of a characteristic of the carrier of the first type is intended by the computing system, determining at least one carrier of the second type, for which reception by the computing system of scheduled communications would be interrupted by the intended measurement of a characteristic of the carrier of the first type; and generating first data for output to the network node, the first data comprising an identification that the intended measurement would cause an interruption to reception, by the computing system, of communications on said at least one carrier of the second type.

According to a further exemplary embodiment, there is provided a computer program comprising a set of instructions for execution by a computing system configured to measure a network resource in a communications network, the network resource having a carrier frequency and the computer program being capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the network node as to be inactive at the computing system, and one or more carriers of a second type, for which the computing system is currently configured to receive communications, in which the set of instructions, when executed by the computing system, cause the computing system to perform thc steps of: responsive to a determination, by the computing system, that a measurement of a characteristic of the carrier of the first type is intended by the computing system, determining a said carrier of the second type, for which reception by the computing system of scheduled communications would be interrupted by the intended measurement of a characteristic of the carrier of the first type; and selectively configuring the computing system to use a predetermined scheduling pattern to perform the measurement based on the determination of whether reception of scheduled communications on the carrier of the second type would be interrupted by the intended measurement, the predetermined scheduling pattern having a measurement slot indicating a time period in which communications are not scheduled with the network node on the carrier of the second type.

According to a further exemplary embodiment, there is provided apparatus for use in controlling communications in a communications network, the apparatus being capable of communicating with a user equipment via a plurality of carriers, each having a different carrier frequency, wherein communications occur over at least one carrier of a first type, for which reception of communications is configured but has been indicated by the apparatus to be inactive at the user equipment, and at least one carrier of a second type, for which the user equipment is currently configured to receive conmiunications, the apparatus comprising a processing system arranged to cause the apparatus to: determine at least one said carrier of the second type for which reception of scheduled communications, by the user equipment, would be interrupted by an intended measurement of a characteristic of the carrier of the first type by the user equipment; and selectively modify the scheduling of communications on the or each said carrier of the second type responsive to the determination.

According to a further exemplary embodiment, there is provided a user equipment for use in controlling communications in a communications network, the user equipment being capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the network node as to be inactive at the user equipment, and one or more carriers of a second type, for which the user equipment is currently configured to receive communications, the user equipment comprising a processing system arranged to cause the user equipment to: responsive to a determination, by the user equipment, that a measurement of a characteristic of the carrier of the first type is intended by the user equipment, determine at least one carrier of the second type, for which reception by the user equipment of scheduled communications would be interrupted by the intended measurement of a characteristic of the carrier of the first type; and generate first data for output to the network node, the first data comprising an identification that the intended measurement would cause an interruption to reception, by the user equipment, of communications on said at least one carrier of the second type.

According to a further exemplary embodiment, there is provided a user equipment for use in measuring a network resource in a communications network, the network resource having a carrier frequency and the user equipment being capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the network node as to be inactive at the user equipment, and at least one carrier of a second type, for which the user equipment is currently configured to receive communications, the user equipment comprising a processing system arranged to cause the user equipment to: responsive to a determination, by the user equipment, that a measurement of a characteristic of the carrier of the first type is intended by the user equipment, determine a said carrier of the second type, for which reception by the user equipment of scheduled communications would be interrupted by the intended measurement of a characteristic of the carrier of the first type; and selectively configure the user equipment to use a predetermined scheduling pattern to perform the measurement based on the determination of whether reception of scheduled communications on the carrier of the second type would be interrupted by the intended measurement, the predetermined scheduling pattern having a measurement slot indicating a time period in which communications are not scheduled with the network node on the carrier of the second type.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings.

Brief Description of the Drawings

Figure 1 is a schematic block diagram of an example of system architecture within which embodiments operate; Figure 2 is a schematic block diagram showing various components of Figure I in further detail; Figure 3 is a schematic state flow diagram showing steps performed by a Node B in order to modi' its scheduling of communications according to an embodiment; Figure 4a is a schematic state flow diagram showing steps performed by a liE in order to compile an affected list for sending to a Node B according to an embodiment; Figure 4b is a schematic state flow diagram showing steps performed by a UE in order to compile an affected list for sending to a Node B according to a further embodiment; Figure 5 is a schematic state flow diagram showing steps performed by a Node B in order to receive an affected list from a liE and modify its scheduling of communications according to an embodiment; Figure 6 is a schematic state flow diagram showing a carrier interruption determination process performed by a Node B according to an embodiment; Figure 7 is a schematic state flow diagram showing steps performed by a UE according to an embodiment, whereby the UE performs a determination of whether an active carrier would be affected by an intended measurement of a deactivated carrier and generates data for output to a network node; Figure 8 is a schematic state flow diagram showings steps performed by a UF according to an embodiment, whereby the UE measures a network resource on the basis of a predetermined scheduling pattern in the event that the FE determines that an active carrier would be affected by an intended measurement of a deactivated carrier; and Figure 9 is a schematic diagram showing sigualling that occurs between a UE, a Node B and an RNC according to an embodiment.

Detailed Description

In the following description it should be noted that the term "apparatus" includes wireless devices and, in general, any device capable of connecting wirelessly to a network. This includes in particular mobile devices including mobile or cell phones (including so-called "smart phones"), personal digital assistants, pagers, tablet and laptop computers, content-consumption or generation devices (for music and!or video for example), data cards, USB dongles, etc., as well as fixed or more static devices, such as personal computers, game consoles and other generally static entertainment devices, various other domestic and non-domestic machines and devices, etc. The term "user equipment" or UE is often used to refer to wireless devices in general, and particularly mobile wireless devices.

Similarly, various passages in this specification make mention of the terms "network", "network control apparatus" and "base station". In this respect, it will be understood that the "network control apparatus" is the overall apparatus that provides for general management and control of the network and connected devices. Such apparatus may in practice be constituted by several discrete pieces of equipment. As a particular example in the context of UMTS (Universal Mobile Telecommunications System), the network control apparatus may be constituted by for example a so-called Radio Network Controller (RNC) operating in conjunction with one or more Node Bs (which, in many respects, can bc regarded as "base stations"). As another example, LTE (Long Term Evolution) makes use of a so-called evolved Node B (eNB) where the RE transceiver and resource management/control functions are combined into a single entity. The term "base station" is used in this specification to include a "traditional" base station, a Node B, an evolved Node B (eN B), or any other access point to a network, unless the context requires otherwise. Moreover for convenience and by convention, the terms "network", "network control apparatus" and "base station" will often be used interchangeably, depending on the context.

Thc description also makcs use of the term "carrier", which gcncrally refers to an allocation of frequency resources in the communications network that can be used for communications, for example between a user equipment and a base station such as a Node B network node. An "active" or "activated" carrier is a carrier on which communications are currently scheduled. A "deactivated" carrier, "inactive" carrier or "configured-but-deactivated" carrier refers to a carrier for which frequency resources have been siialled but for which no communications are currently scheduled. Such a deactivated carrier is therefore configured for communications in the communications network but is inactive as a consequence of the lack of scheduled communications on that deactivated carrier. For example, in a HSDPA system, a Node B can schedule communications on at least the primary carrier and one or more secondary carriers, and can avoid scheduling on selected other secondary carriers.

The indication of whether a secondary carrier is currently deactivated can be sent to a UE from the Node B via a High Speed Shared Control Channel (HS-SCCH) in a HS-SCCH order. The configured carriers in HSDPA are each known as a IJARFCAN (IJMTS absolute radio frequency channel number).

Embodiments are concerned with controlling communications in various types of communications networks, an example of such a network being shown in Figure 1 of the accompanying drawings. Figure 1 shows schematically se'ected parts of a communications network 100, such as a UMTS (Universal Mobile Telecommunication System) network suitable for 1-ISPA operations, and in particular, I-ISDPA. The communications network 100 comprises a plurality of liEs 102, a Node B 104 and a plurality of cells 106 associated with the Node B 104. Each of the plurality of cells 106 corresponds to different range of frequencies associated with the Node B I 04. Tn this example, a first cell 106-1, a second cell 106-2 and a third cell 106-3 are associated with the Node B 104. The cells are depicted as hexagons for illustrative purposes only and it will be appreciated that the coverage of each cell is dependent on the transmissions of the associated Node B 104. The Node B 104 operates in accordance with instructions and data received from a Radio Network Controller (RNC) 108, which can coordinate transmissions of thc Node B 104. While Figure 1 shows the RNC 108 as a component that is physically separate from the Node B component, the skilled person will appreciate that the RNC 108 and the Node B 104 can be physically combined, while maintaining the TO logical separation that distinguishes operations and interfaces of an RNC from those of a Node B. Each liE 102 is arranged to receive communications via at least a primary carrier associated with a primary cell 106. All other cells that may communicate with the UE 102 are known as secondary cells with respect to that UE 102. Any communications received by the TiE 102 from a secondary cell is received via a secondary carrier. In this example, a first liE 102-1 uses a first cell 106-1 as its primary cell and as such is configured to receive communications via a primary carrier associated with the first cell 106-I. Any communications received via the secondary cells 106-2, 106-3 are received via secondary carriers associated with those secondary cells 106-2, 106-3.

When a liE 102 communicates with a Node B 104 using, for example, MC-HSDPA, it can receive communications via its primary carrier alone, or via its primary carrier and also one or more secondary carriers. Therefore, each of the first, the second and the third UEs are capable of receiving communications by aggregating or multiplexing communications received on their primary carrier with one or more secondary carriers.

Figure 2 shows schematically a user equipment T 02 or wireless device, in this case in the form of a mobile phone/smartphone. The user equipment 102 contains the necessary radio module 110, processor(s) and memory/memories 112, antenna1antennas 114, etc. to enable wireless communication with the communications network. The user equipment 102 in use is in communication with a radio mast 104. As a particular example in the context of UThVITS (Universal Mobile Telecommunications System), there may be a network control apparatus 108, which may be constituted by for example the afore-mentioned Radio Network Controller (RNC), operating in conjunction with one or more Node Bs 104. The network control apparatus 108 may have its own processor(s) 116 and memory/memories 118, etc. The TiE 102 can comprise various receiver chain configurations in accordance with a MC-HSDPA architecture. For example, the liE 102 can be designed with a single-receiver chain having a bandwidth configured to receive communications over the various carrier frequencies of the multiple carriers in the MC-HSDPA architecture. In the example of Figure 1, the first LiE 102-1 has a single-receiver chain configured with a bandwidth to receive at least its primary carrier and one or more secondary carriers. For example, when receiving on only its primary carrier, the first tiE 102-1 maybe configured with a bandwidth ofs MFIz. Ifthe first LiE 102-1 wishes to receive its primary carrier plus one of the secondary carriers associated with secondary cells 106-2, 106-3, which secondary carriers are adjacent in carrier frequency to the primary carrier (and therefore also known as contiguous carriers), then the first tiE 102-1 may be configured with a bandwidth of 10 MHz. Ifthe first TiE 102-1 wishes to receive its primary carrier plus both of the contiguous secondary carriers associated with secondary cells 106-2, 106-3, then the first TIE 102-1 may be configured with a bandwidth of 15 MHz.

In another example, the TIE can be provided with a multiple receiver chains, such that communications on different carriers can be received via different receiver chains. For example, the TiE 102 can comprise dedicated receiver chains for each carrier as well as receiver chains with broad bandwidths designed to receive multiple carriers.

When a TiE 102 is operating in a communications network 100 that uses MC-HSDPA protocols, communications with the TIE 102 are typically scheduled by a Node B 104 on a plurality of active carriers (including the primary carrier and at least one secondary carrier). If the Node B 104 determines that a particular secondary carrier is to be deactivated such that no communications are to be scheduled on that secondary carrier, then the Node B 104 compiles a HS-SCCH order for sending, via the HS-SCCH, to the UE 102 in order to inform the TiE that the secondary carrier is deactivated. In response to receiving the HS-SCCH order, the TiE 102 can determine whether or not it can reconfigure its rcccivcr to increase or optimise the TIE's performance. For example, in the case that the TiE 102 has a single-receiver chain configured for reception of communications on multiple carriers and one of the multiple carriers is the indicated deactivated carrier, the tiE 102 can determine whethcr or not thc recciver bandwidth can bc adjusted in a re-tuning process in order to exclude the carrier frequency of the secondary carrier whilst maintaining a bandwidth that includes the carrier frequencies of the active carriers. If the TiE 102 determines that such a re-tuning can take place then it can re-tune its receiver bandwidth so as to avoid rcccption of communications on thc dcactivatcd carrier. By narrowing its bandwidth to exclude the deactivated carrier, the TIE 102 can reduce its power consumption, improve downlink performance for the active carriers, and avoid RF image interference. In the case where the tiE 102 has a multiple-receiver chain structure with the deactivated carrier being associated with a receiver chain other than the receiver chain (or chains) used to receive communications on the active carriers, then the TIE 102 simply responds to the HS-SCCH order by switching off its receiver chain for that deactivated carrier in order to improve its performance.

From time-to-time, the RNC 108 may signal the tiE 102 to perform a measurement of a characteristic of the deactivated carrier, for example, to be used by the RNC 108 in making mobility decisions. For example, the characteristic to be measured may be the received signal code power (RSCP) or Bc/Jo ratio of a control pilot channel (CPICH) associated with the deactivated carrier. RSCP is an estimate of the power received from the control pilot channel (CPICH). The Echo is a signal to noise ratio of the CPICH, where "Ee" is the received energy per chip (i.e. code bit) and the "lo" is the interference level, usually given in dB. The measurement may be associated with reporting the so-called "event 2c" defined in 3GPP, which is when the estimated quality of a non-used frequency (i.e. the deactivated carrier) is determined to be above a certain threshold (e.g. a Ec/lo threshold of-16 dB). The event 2C report could be used, for example, to trigger a swap of the primary and secondary frequencies for uplink load balancing purposes. In order to perform the relevant measurement, the TiE 102 must reconfigure its receiver to receive over the deactivated earner.

For the single-receiver case, this means ceasing communications (i.e. and therefore interrupting reception of communications) on the active carriers in order to re-tune its receiver bandwidth so as to receive the deactivated carrier. The measurement can then be performed and sent to the Node B 104 before then re-tuning the receiver bandwidth once again to exclude the deactivated carrier. For the multiple-receiver case, the receiver chain for the deactivated carrier is switched on so that the measurement can be performed and sent to the Node B 104 before the receiver chain is then turned off again. Depending on the specific receiver design of the UE 102, the switching on of the receiver chain to pcrform the measurcment of the deactivated carrier could cause an interruption or temporary degradation to the communications on the active carriers due to local oscillator pulling. In both the single-receiver chain and the multiple-receiver chain cases, the interruption of the reception of communications on the active carriers due to the measurement of the deactivated carrier causes the UE 102 to miss receiving scheduled communications thereby resulting in data packet losses at the UE 102 and an inefficient system. In particular, if a TIE 102 is being scheduled on the HS-SCCH or HS-PDSCH (High Speed Physical Downlink Shared Channel), then it is the rate of measurement activity that will determine the amount of HS-SCCH/HS-PDSCH loss. For example, if it is assumed that measurement activities are performed by the UE 102 every 80 ms and the interruption before and after the measurement affects one subframe of received data, then there could be a packet loss rate of five percent due to the two retuning events and the loss of both HS-SCCH and HS-PDSCH during the re-tuning.

Figure 3 shows a schematic state flow diagram of a method of controlling communications in the communications network I 00 of Figure I according to a first exemplary embodiment. in this embodiment it is assumed that there is at least one carrier of a first type, for which reception of communications is configured but has been indicated by the network node to be inactive at the user equipment. The carrier of the first type is said to be inactivc as a consequence of no communications being schcdulcd by the Node B on that carrier, and the carrier is therefore a deactivated carrier. It is also assumed that there is at kast one carrier of a second type, for which the user equipment is currently configured to receive communications. The carrier of the second type is therefore an active carrier.

At step 300, the method comprises determining at least one said carrier of the second type for which reception of scheduled communications, by the user equipment, would be interrupted by an intended measurement of a characteristic (e.g. Ec/lo, RSCP) of the carrier of the first type by the user equipment. The carrier of the second type for which reception of scheduled communications is interrupted is known as an "affected" carrier. The scheduling of communications on the or each said carrier of the second type is selectively modified in step 302, responsive to the determination.

In some examples, the determination of the affected carrier in step 300 is based on data received from the TiE 102, in accordance with the processes described with reference to Figures 4 and 7. In other examples, the determination of the affected carrier in step 300 is based on a carrier interruption determination process described with reference to Figure 6.

Figure 4a shows a schematic flow diagram of processes that may be performed by the TiE 102 in the communications network 100 and that enable the Node B 104 to perform the determination described above with reference to step 300 of Figure 3.

This assumes that the UF 102 has received data from the Node B 104 to enable the UE 102 to be configured for communications with the communications network 100 using a plurality of carriers, including the aforementioned active and inactive carriers.

These data can have been sent at any point prior to the TiE 102 performing the method now to be described, and, once the carriers have been configured by the TiE 102 in accordance with these data, the FE 102 can then receive scheduled communications via the carriers (i.e. as active carriers) from the Node B 104 (step 400).

At step 402, the UE 102 determines whether or not a measurement is, or may be, required for a characteristic (e.g. RCSP, Echo) of the deactivated carrier. This step maybe performed in response to signalling from the Node B 104 indicative that a measurement of an inactive carrier is required, or it may be performed by the TiE 102 based on its knowledge of various carrier configurations that has been previously sent by the Node B 104. If it is determined at step 402 that no such measurement of a deactivated secondary carrier is required then the process returns to step 400, whereby the TiE 102 continues to receive communications on the active carriers. If it is determined that a measurement of what is, or would be in the ffiturc, a deactivated secondary carrier is intended then the process moves onto step 404, where it is determined if one or more active carriers would be likely to be impacted by such a measurement (i.e. it is determined whether or not the IJE receiver will likely require reconfiguration and if such reconfiguration would affect or interrupt reception of communications on any of the active carriers). If, at step 404, it is determined that none of the active carriers are likely to be affected by the intended measurement, then the process returns to step 400 whereby the UE 02 continues to receive communications on the active carriers.

If it is determined that one of more active carriers are likely to be affected by the intended measurement, then the process moves onto step 406 whereby the UE 102 compiles a list of active carriers that are likely to be affected (i.e. the "affected carrier list") by the intended measurement for sending to the Node B 104.

Figure 4b shows an arrangement in which the UE 102 determines the list of active carriers in advance of any carrier being deactivated or any such deactivated carrier being measured. Specifically, the TiE 102 can execute an algorithm configured in accordance with the following IF.. .TI-IEN statement: IF the node B happens to deactivate carrier X THEN the following carriers [...] will be affected IF they are active The UE 102 can use the output from this algorithm in order to compile, for each carrier when deactivated, a listing of all other carriers, when active, that are likely to be affected by a measurement of that deactivated carrier.

At step 450, the UE 102 selects a secondary carrier "n" for which the UE 102 is configured to receive communications (i.e. regardless of whether that carrier is activated or deactivated). The configured carrier is assumed at the UE 102 to be a deactivated carrier. Then, at step 452, the TiE 102 selects one of the configured carriers "k" other than the carrier "n", typically but not necessarily starting from the primary carrier. At step 454, the UE 102 determines whether or not the carrier "k" would be affected by a measurement of the deactivated carrier "n" and stores the result in memory. At step 456, the TilE 102 determines whether or not each and every configured carrier "k" at step 452 has been evaluated with respect to carrier "n". If not, the process moves to step 458, at which point the process of step 452 is incremented so that the next configured carrier "k+1" can be evaluated. If at step 456 it is determined that all the carriers have been evaluated, then the process moves to step 460. At step 460, the UB 102 determines whether or not data has been evaluated and stored with respect to each and every one of the configured secondary carriers that can be set as an assumed deactivated carrier. If not, the process moves onto step 462 whereby the process of step 450 is incremented so that the next configured secondary carrier "n+l" can beset as an assumed deactivated carrier. If at step 460, it is determined that data has been stored for all of the configured carriers as assumed deactivated carriers, then the process moves onto step 464 where an affected list is compiled for sending to the network (e.g. Node B, RNC or combined Node B and RNC). The affected list is therefore compiled in order to list, for each carrier that is deactivated, all of the carriers that would be affected by a measurement of the particular carrier that is deactivated. It will be appreciated that the evaluations need not be carried out for each carrier one-by-one, but can be carried out for all carriers at the same time.

Referring back briefly to step 302 of Figure 3, the Node B 104 can use the affected carrier list to control or modify its scheduling of communications on the active carriers so as to avoid any scheduling during a time period for when the measurement is intended to take place. This in turn reduces data packet loss at the liE 102 because the Node B can then avoid scheduling on the active carriers at times where the UE 102 is unable to receive communications or reception of communications is otherwise interrupted. After sending the affected carrier list to the UE 102, the VE 102 then performs reconfiguration of its receiver and proceeds to take the intended measurement before reverting back to its original configuration. For example, at step 408 of Figure 4a, responsive to the determination that at least one active carrier is to be affected, the UE 102 makes use of a predetermined scheduling pattern such as a "compressed mode" pattern, which is known to both the Node B and the UE 102, so as to determine when the intended measurement should be made. A suitable compressed mode (CM) pattern may use the same parameters as defined by "legacy" CM in 3GPP TS2S.331 and TS25.133, as will be described in more detail below with reference to Figure 8. In one embodiment these parameters are signalled from the RNC 108 and therefore the RNC 108 is aware of the timing of the intended measurement and can accordingly coordinate the Node B 104 with the UE 102 to avoid scheduling when the tiE receiver is being reconfigured and the measurement is being performed. The compressed mode is therefore selectively used when a measurement of a deactivated carrier is required and when it has been determined that such a measurement would impact one or more active carriers.

Figure 5 shows a schematic flow diagram of processes that are performed by the Node B 104 when cooperating with a UE 102 configured to perform certain steps described above with reference to Figures 4a and 4b. This example assumes that the Node B has previously sent an aforementioned HS-SCCH order to the TiE, which results in one or more secondary carriers being inactive at the liE. Thereafter, the RNC 108 may decide that measurements for the deactivated carrier are required, for example, in order to perform handover decisions. Accordingly, the RNC 108 signals to the Node B 104 an indication that a measurement of the deactivated carrier is required and the Node B 104 indicates to the UE 102 that the deactivated secondary carrier requires measuring. Based on the indication, the tiE 102 performs a process, such as is described above with reference to step 404 of Figure 4a, to determine whether or not any active carriers would likely be affected by the measurement and compiles a list of the determined affected active carriers for sending to the Node B 104. At step 500, the Node B 104 receives the affected carrier list from the liE 102 and then determines from the list, which of the active carriers would be affected by the intended measurement (step 502). The Node B 104 uses this information in step 504 to accordingly modify its scheduling of communications on the active carriers so as to avoid scheduling when the measurement of the deactivated secondary carrier is intended. For example, as the Node B is aware of compressed mode parameters that are to be used at the liE 102 indicating when to perform the intended measurement, the Node B can therefore determine when the TilE will likely perform the measurement. As such, the Node B 104 can coordinate its scheduling with the measurement process that is to occur at the TiE 102.

Figure 6 shows a schematic state flow diagram of a carrier interruption determination process that is performed by the Node B 104, which enables the Node B 104 to determine which active carriers are to be affected by an intended measurement of a deactivated carrier (step 300 of Figure 3). At step 600, the Node B 104 identifies which of the plurality of carriers are active and which carriers are deactivated. The Node B 104 also identifies the deactivated carrier for which a measurement is intended. The Node B 104 is capable of performing these identifications because it knows which carriers are configured for communications with the UE 102, and which of those carriers are currently being scheduled. After performing the identification, the Node B 104 then obtains information about allocated frequencies for each identified carrier. A comparison process is then performed in steps 602, 604 and 606 to determine whether the intended measurement would interrupt reception of communications on an active carrier on the basis of whether the active carrier is within a frequency band utilised by the deactivated carrier (i.e. and the carriers are therefore intra-band) and in dependence on whether the deactivated carrier is adjacent to one or more active carriers. For example, the Node B 104 may determine that reception of a given active carrier would be interrupted by the measurement when the following is true: (i) the given active carrier is adjacent to a second active carrier; (ii) the given active carrier is adjacent to the deactivated carrier; and (iii) a plurality of said active carriers and the deactivated carrier are intra-band.

As another example, the Node B 104 may determine that reception of a given active carrier would be interrupted by the measurement when the following is true: (i) the given active carrier is adjacent to a second active carrier; (ii) the second active carrier is adjacent to the deactivated carrier; and (iii) the given active carrier, second active carrier and the deactivated carrier are intra-b and.

In particular, the comparison process begins at step 602, where the Node B 104 performs a comparison between the carrier frequency of the deactivated carrier to be measured and the carrier frequencies of the active carriers.

At step 604, it is determined, for each active carrier, whether a selected one of the active carriers and the deactivated carrier are in a same frequency band (i.e. intra-band). If the selected active carrier and the deactivated carrier are determined not to be in the same frequency band, and are therefore inter-band, the Node B 104 assumes that the selected active carrier would not be impacted by a measurement of the deactivated carrier and the processing returns to step 600. Altematively, the process could move onto step 610, which is described below. If the selected active carrier and the deactivated carrier are determined at step 604 to be intra-band, the process then moves onto step 606 where an assessment is made to determine whether or not the deactivated carrier has a carrier frequency between that of the selected active carrier and at least one other active carrier. If so, then the Node B 104 assumes that the liE receiver does not require any reconfiguration (i.e. the receiver chain bandwidth does not need re-tuning) and thus the selected active carrier would not be impacted by a measurement of the deactivated carrier. The process then returns to step 600. If however, it is determined at step 606 that the deactivated carrier is not between the selected active carrier and another active carrier, then the Node B 104 assumes that the receiver chain of the liE 102 is likely to exclude the deactivated carrier and therefore requires a re-tuning in order to perform the intended measurement. The Node B 104 assumes that such a re-tuning would impact the liE's reception of communications on the selected active carrier (thus being determined as an "affected carrier"). The process then moves onto step 608 in which the Node B 104 adjusts its scheduling on the selected, or affected, carrier so as to avoid scheduling on this affected carrier when the measurement is being performed. More specifically, as the Node B is aware of when it sent the indication to the liE 102 that a measurement of the deactivated carrier is required, it can predict when the liE 102 is likely to perform the measurement (and hence also the re-tune its receiver). The Node B 104 can therefore avoid scheduling the liE 102 on the affected carrier during the expected time of the intended measurement. For example, the Node B 104 may assume that thc LIE 102 uses the aforementioned compressed mode parameters to schedule the intended measurement and therefore modifies its scheduling in accordancc with thcsc parametcrs. Steps 604 to 608 arc repeated for each identified active earner.

An additional step 610 can optionally be used by the Node B 104 to determine a receiver configuration of the UB 102 when it is determined that the selected active carrier and the deactivated carrier arc inter-band. This is because, although the carriers are determined to be inter-band, it is still possible for the selected active carrier to be impacted by a measurement of the deactivated carrier, depending on the TJE's receiver configuration. The receiver configuration can be signalled to the Node B 104 from the UE 102 or can be determined by the Node B based on attributes of the TJE 102 (e.g. device manufacturer identifier). For example, where the TiE 102 uses a multiple-receiver chain, with separate receiver chains for the deactivated carrier and selected active carrier, it is expected that the receiver chain for the deactivated carrier is switched off (assuming that receiver chain is not also currently configured to receive any of the active carriers). In such a case, the receiver chain for the deactivated carrier will require switching on in order to perform the intended measurement, and the switching on could cause local oscillator pulling on the selected active carrier, thus impacting reception of communications on the selected active carrier. If it is determined by the Node B, based on the UE 102 receiver configuration and the frequencies of the selected active carrier and the deactivated carrier, that local oscillator pulling would likely impact reception of communications on the selected active carrier, then the process moves on to step 608. The Node B then accordingly modifies its scheduling for the selected active carrier (i.e. the affected carrier). If no local oscillator pulling is determined to occur, the process moves to step 600.

The various possible determinations by the process shown in Figure 6 will now be described with reference to several case examples.

Case 1: Multiple contiguous carriers in the same frequency band using a single-receiver chain, where the deactivated carrier is adjacent to two or more active carriers, e.g. is in between two of those carriers. In this ease, as the deactivated carrier is between two of the active carriers, the receiver bandwidth cannot be narrowed to exclude only the deactivated carrier and therefore reception of either of the adjacent active carriers is expected not to be affected by measurement activity on the deactivated carrier. The Node B can therefore schedule communications on the active carriers without any modification.

Case 2: Multiple, contiguous carriers in the same frequency band received using a single-receiver chain, where the deactivated carrier is adjacent to at least one active carrier and is not between any two active carriers. In this case, the receiver bandwidth is likely to have been narrowed to exclude the deactivated carrier and therefore any measurement activity on the deactivated carrier is likely to affect the adjacent active carrier(s). The Node B should therefore modify its scheduling of communications on the active carriers to avoid scheduling when the intended measurement is to be performed.

Case 3: Multiple carriers on different frequency bands, at least one receiver chain for the active carriers and another receiver chain for the deactivated carrier (which another receiver chain is not shared with any active carriers). In arrangements in which step 610 is not performed, measurement activity on the deactivated carrier will be assumed not to affect the reception of the active carriers. The Node B can therefore schedule communications on the active carriers without any modification.

In arrangements in which step 610 is performed, if it is determined that local oscillator pulling is likely to affected an active carrier then the Node B should therefore modify its scheduling of communications on the active carriers to avoid scheduling when the intended measurement is to be performed.

Case 4: Multiple, contiguous carriers in the same frequency band received using a single-receiver chain, where the deactivated carrier is non-contiguous with one or more active carriers and is not between any two active carriers. In this case, it is assumed that the receiver bandwidth is likely to have been narrowed to exclude the deactivated carrier and therefore any measurement activity on the deactivated carrier is likely to affect the adjacent active carrier(s). The Node B should therefore modi' its scheduling of communications on the active carriers to avoid scheduling when the intended measurement is to be performed.

Figure 7 shows a schematic flow diagram of processes that are performed by the UE 102 in the communications network 100, whereby the liE 102 performs a determination of whether an active carrier would be affected by an intended measurement of a deactivated carrier and generates data for output to a network node (e.g. Node B, RNC or combined Node B and RNC). This Figure broadly corresponds to steps 400 to 406 described above with reference to Figure 4a and steps 450 to 464 described with reference to Figure 4b. At step 700, the VE 102 determines that a measurement of a characteristic (e.g. Ec/lo, RSCP) of a carrier of a first type (for which reception of communications is configured but is indicated by a network 100 as to be inactive at the UE 102) from a plurality of carriers is intended. For example, this determination is based on a message received from the Node B 04 that the mcasurcmcnt is rcquircd. The DE 102 also determines at least one carricr of the second type (i.e. an active carrier), for which reception by the user equipment of scheduled communications would be interrupted by the intended measurement of a characteristic of the carrier of the first type. At step 702, the tiE 102 generates first data for output to a network node. The first data comprises an identification that the intended measurement would cause an interruption to reception, by the user equipment, of communications on said at least one carrier of the second type. The identification of the affected active carrier therefore allows the network node to modify its scheduling of communications on the affected active carrier so as to avoid any data packet losses at the UE during the measurement. In an alternative example, the first data comprises an identification of the deactivated carriers for which a measurement is intended. For example, where there may be several deactivated carriers, the identification of which one of the deactivated carriers to be measured therefore allows the first data to be used to determine which active carriers would be affected by the measurement.

In some examples, and indeed as exemplified by step 406 described above with reference to Figure 4a and step 464 of Figure 4b, the first data comprises information listing which active carriers would be affected by a measurement of the deactivated carrier. For example, in a 3C-HSDPA system having a first UARFCN (Fl), a second UARFCN (F2) and a third UARFCN (F3), where Fl and F2 are adjacent to one another in a first frequency band (and therefore contiguous and intra- band) and F3 is in a second frequency band (and therefore non-contiguous and inter-band with respect to Fl and F2), a UE 102 may use a first receiver chain to receive communications via Fl and F2 and a sccond rccciver chain to rcecivc communications via F3. The various different active carrier(s), depending on which carrier is inactive, is/are shown in Table 1.

Deactivated carrier to be measured Affected active carriers Fl F2 F2 Fl F3 -Table 1. First data showing affected carriers (if active) for each carrier, when deactivated, is to he measured.

As shown in Tablc 1, if Fl is dcactivatcd and is to be mcasurcd, F2 whcn activc would be impacted by such a measurement. If F2 is deactivated and is to be measured, Fl when active would be impacted by such a measurement. If F3 is deactivated and is to bc measured, no carricrs would bc impacted by such a measurement (subjcct to a detcrmination whethcr or not any carricrs would bc affcctcd duc to rcccivcr architccturc and possible local oscillator pulling).

As described with reference to Figures 4a and 4b, the first data can be sent to the Node B 104 when a measurement indication has been received or ahead of any scheduling and independent of when measurements of deactivated carriers are actually required.

The first data can be sent to the network node as a part of a "RRCConnectionSetupComplete" message or a "UECapabil itylnformation" message in response to receiving the measurement indication or during the setup procedure of the UE 102. The first data may also be signalled in an RRC reconfiguration response message, for example, when the network configures or dc-configures multi-carrier HSDPA.

In one arrangement, and as briefly mentioned above, embodiments make use of the legacy compressed mode (CM) as defined in 3GPP TS2S.331 in order to signal to the Node B those active carriers for which reception would be interrupted by an intended measurement of an inactive carrier. This is a particularly convenient mechanism to use because the compressed mode inherently includes time gaps within which communications are not transmitted between the UE 102 and the Node B 104.

Further, these gaps are synchronized between the liE 102 and the Node B 104, meaning that the LE 102 simply has to notify the Node B 104 that it will use CM, and provide details of the carriers that would be affected by an intended measurement, thereby enabling the Node B 104 to schedule communications accordingly in the manners described above. It is to be noted that this is an entirely new and unexpected use of the legacy CM mechanism. Further details of how the mode is configured for this usc arc provided below, with rcfcrcncc to Figurc 8.

In the case where the first data is to be included as part of a RRCConnectionSetupComplete message, the RRCConnectionSetupComplete as defined by 3GPP TS25.331 (see section 10.2.41) can be modified, for example, to include the following additional information shown in Table 2 and Table 3.

Information Need Multi Type and Semantics

Element/Group name reference description

Other information elements MeasurementsWithout OP Measurem Presence indicates CM Info entsWitho that the UE can utCM Info perform I 0.x.x.x measurements of configured carriers without compressed mode _____________ ____ ____ ______ (CM) Table 2. Additional information (first data) for RRConnectionSetupComplete message.

The "MeasuremcntsWithoutCM Info" information clement is indicated for each secondary carrier when deactivated and if measurement activity on the secondary carrier affects reception of the primary carrier or other secondary carrier. The presence of this information element (IE) indicates that measurements are currently to be made on an inactive carrier without compressed mode, while the absence of this IE indicates that measurements are to be made on an inactive carrier with compressed mode. Table 3 sets out the content of this IE, in the event that use of CM for performing measurements is siwialed to the Node B. Information Need Multi Type and Semantics description Element! reference Group name Secondary MP I to7 cell Measurement sWithoutCM Info List Primary Cell OP Enumerate True indicates that if this Reception d (TRUE) secondary carrier is Impact deactivated, measurements will have impact to the reception of the primary carrier Secondary OP BITSTRI A"!" indicates that if this Cell NG (7) secondary carrier is Reception deactivated, measurements impact will have impact to the reception of another secondary carrier. Bit 0 corresponds to secondary carrier 0, bit 1 corresponds to secondary carrier I,...

Default value is: Secondary carrier deactivation does not have impact to the reception of any other secondary carrier. Bit 0 is the first/leftmost bit of the bit ___________________ __________ _________ _______________ string Table 3. Additional information (first data) for RRConnectionSetupComplete message.

The column entitled "Semantics description" in Table 3, describes the effects of measuring a deactivated secondary carrier. In the "Primary Cell Reception Impact" row, a "Enumerated (TRUE)" field indicates that the measurement of the secondary carrier would impact the primary carrier. In the "Secondary Cell Reception Impact" row, a bit string field is used to indicate, which, if any, other secondary carriers would be affected by the intended measurement.

In the case where first data is to be included as part of a UECapabilitylnformation message, the UECapabilitylnfomiation message as defined by 3GPP TS2 5.101 can be modified, for example, to include an "interruption indicator flag. The precise nature of the flag will depend on which configurations the UE 102 has signalled it can support: for example, the LIE 102 may support single band configurations and dual band configurations, and variants on each of these dependent on operating band, and number of downlink carriers within the or each operating band(s).

For the case of the single band sets of various MC-HSDPA configurations, and for each supported band configuration, an additional one bit can be added to the UECapabilitylnformation message (i.e. representing the interruption indicator flag).

Considering first single band 4C-HSDPA, this is designed to operate in the following configurations: Single band 4C-Operating Number of DL HSDPA Band carriers Configuration __________ __________________ 1-3 I 3 11-3 II 3 11-4 II 4 NOTE: Single band 4C-HSDPA configuration is numbered as (X-M) where X denotes the operating band and M denotes the number of DL carriers.

Table 4. Single band 4C-HSDPA configurations As an example, if a liE 102 supports 1-3 and 11-4, the interruption indicator flag for 1-3 could be set to TRUE and the interruption indicator flag for 11-4 could be set to FALSE. A flag set to TRUE means that measurements of a deactivated carrier would cause interruption to all the other received carriers in the band.

Considering next dual band 4C-HSDPA, this is designed to operate in the following configurations: Dual band 4C-UL DL Number of DL. DL Number of HSDIPA Band Band carriers in Band A Band DL Configuration A B carriers in _____________ ______ _____ _____________ _____ Band B I-2-VIII-1 I 2 VIII 1 I-2-VIII-2 I 2 VIII 2 I-1-VIII-2,4'I I 1 VIII 2 I-3-VIII-1 I 3 VIII 1 II-1-IV-2 II or IV II I IV 2 11-2-tv-I II or IV II 2 IV I II-2-IV-2 II or IV II 2 IV 2 I-1-V-2 IorV I I V 2 I-2-V-l IorV I 2 V 1 I-2-V-2 IorV I 2 V 2 II-l-V-2 IIorV II I V 2 NOTE: Dual band 4C-HSDPA configuration is numbered as (X-M-Y-N) where X denotes the DL Band A, M denotes the number DL carriers in the DL Band A, Y denotes the DL Band B, and N denotes the number of DL carriers in the DL Band B Table 5. Dual band 4C-HSDPA configurations For dual band sets, two interruption indicator flags could be used. For example, if the UE 102 indicates support for combination II-2-IV-2, then there is a corresponding interruption indicator flag for band II and band IV.

Moving onto single band NC-4C-HSDPA, this is designed to operate in the following configurations: Single band Operating Number of DL Cap Number of DL INC-4C-Band carriers in one between carriers in the HSDPA subblock subblocks other subblock Configuration __________ _______________ IMHzl ________________ I-I-S-I I I 5 1 1-2-5-1 I 2 5 1 1-3-10-1 I 3 10 1 TV-I-S-I IV 1 5 1 IV-2-10-1 IV 2 10 1 IV-2-15-2 IV 2 15 2 IV-2-20-1 IV 2 20 1 IV-2-25-2 IV 2 25 2 NOTE: Single band NC-4C-HSDPA configuration is numbered as (X-M-Y-N) where X denotes the operating band, M denotes the number of DL carriers in one subblock, Y denotes the gap between subblocks in MHz and N denotes the number of DL carriers in the other subblock. M and N can be switched Table 6. Single band NC-4C-HSDPA configurations A similar process applies for the non-contiguous HSDPA combinations (e.g. NC-4C-FISDPA), except that a first interruption indicator flag will be present for a first "sub-block" of frequencies, and a second interruption indicator flag will be present for the other sub-block of frequencies. The underlying assumption here is that if there is an interruption on one band/sub-block, all of the carriers on that band/sub-block are interrupted.

Figure 8 shows a schematic flow diagram of processes that are performed by the UE 102, whereby the UE 102 measures a network resource on the basis of a predetermined scheduling pattern in the event that the UE determines that an active carrier would be affected by an intended measurement of a deactivated carrier. At step 800, the liE 102 determines that a measurement of a characteristic (e.g. Fe/b, RSCP) of a carrier of a first type (for which reception of communications is configured but is indicated by a network 100 as to be inactive at the HE 102) from a plurality of carriers is intended. For example, this determination is based on a message received from the Node B 104 that the measurement is required, such as is shown as step 402 in Figure 4a. The UE 102 also determines at least one carrier of the second type (i.e. an active carrier), for which reception by the user equipment of scheduled communications would be intermpted by the intended measurement of a characteristic of the carrier of the first type. At step 802, the user equipment is selectively configured to use a predetermined scheduling pattern (e.g. compressed mode) to perform the measurement based on the determination of whether reception of scheduled communications on the carrier of the second type would be interrupted by the intended measurement. The predetermined scheduling pattern has a measurement slot indicating a time period in which communications are not scheduled with the network node on the carrier of the second type.

As mentioned above, thc comprcsscd modc (CM) may usc thc same parameters as the legacy CM defined in 3GPP TS25.331 and TS25.133. However, unlike the legacy CM, exemplary embodiments merely use the CM parameters to define when a measurement can be performed. The currently defined standards state that a UE can "activate or deactivate" (i.e. reconfigure) its receiver for an activated or deactivated carrier autonomously, without using compressed mode. In exemplary embodiments, the compressed mode is selectively used when a measurement of a deactivated carrier is required and when it has been determined that such a measurement would impact one or more active carriers. The selective use of the compressed mode means that in cases where no active carriers are affected by the measurement, the UE 102 can still reconfigure its receiver for an activated or deactivated carrier without using compressed mode. However, when it is determined that an active carrier is affected by the measurement, the compressed mode can be used for that measurement. The parameters for compressed mode are signalled from the RNC 108 and therefore the RNC 108 is aware of the timing of the intended measurement and can accordingly coordinate the Node B 104 with the UE 102 to avoid scheduling when the UE receiver is being reconfigured and the measurement is being performed. In particular, CM defines a Transmission Gap (TG) within which the measurement can be performed.

The TJE 102 can alternatively use one or more of the following parameters indicated by a "DPCI-l Compressed Mode Info" information element in order to perform the measurement: TGPRC (Transmission Gap Pattern Repetition Count), TGSN (Transmission Gap Starting Slot Number), TGLI (Transmission Gap Length 1), TGL2 (Transmission Gap Length 2), TGD (Transmission Gap start Distance) and TGPLI (Transmission Gap Pattern Length). As the Node B 104 will be synchronised with (i.e. by virtue of using common Connection Frame Number (CFN)) and aware of the compressed mode pattem that is used by the UB 102, predictions can be made of when the UE 102 is likely to perform the measurement, for example, during the measurement slot or a "transmission gap" of the compressed mode. The Node B 104 therefore modifies its scheduling on the affected carriers to avoid any scheduling during the transmission gap.

Figure 9 shows a schematic diagram of the signalling in the communications network 100 between the UE 102, the Node B 104 and the RNC 108, which consolidates the various steps performed by the UE 102 and Node B 104 described above.

The above embodiments are to be understood as illustrative examples of the invention. Further embodiments of the invention are envisaged.

Although at least some aspects of the embodiments described herein with reference to the drawings comprise computer processes performed in processing systems or processors, the invention also extends to computer programs, particularly computer programs on or in a canier, adapted for putting the invention into practice.

The program may be in the form of non-transitory source code, object code, a code intermediate source and object code such as in partially compiled form, or in any other non-transitory form suitable for use in the implementation of processes according to the invention. The carrier may be any entity or device capable of carrying the program. For example, the carrier may comprise a storage medium, such as a solid-state drive (SSD) or other semiconductor-based RAM; a ROM, for example a CD ROM or a semiconductor ROM; a magnetic recording medium, for example a floppy disk or hard disk; optical memory devices in general; etc. It will be understood that the processor or processing system or circuitry referred to herein may in practice be provided by a single chip or integrated circuit or plural chips or integrated circuits, optionally provided as a chipset, an application-specific integrated circuit (ASIC), field-programmable gate anay (FPGA), digital signal processor (DSP), etc. The chip or chips may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor or processors, a digital signal processor or processors, baseband circuitry and radio frequency circuitry, which are configurable so as to operate in accordance with the exemplary embodiments. In this regard, the exemplary embodiments may be implemented at least in part by computer software stored in (non-transitory) memory and executable by the processor, or by hardware, or by a combination of tangibly stored software and hardware (and tangibly stored firmware).

It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

Claims

CLAIMS1. A method of controlling communications in a communications network, the communications network comprising a network node and a user equipment capable of communicating with the network node via a plurality of carriers, each having a different carrier frequency, wherein communications occur over at least one carrier of a first type, for which reception of communications is configured but has been indicatcd by the nctwork nodc to bc inactivc at thc uscr equipment, and at least onc carrier of a second type, for which the user equipment is currently configured to receive communications, the method comprising: determining at least one said carrier of the second type for which reception of scheduled communications, by the user equipment, would be interrupted by an intended measurement of a characteristic of the carrier of the first type by the user equipment; and selectively modifying the scheduling of communications on the or each said carrier of the second type responsive to the determination.
2. A method according to claim 1, further comprising: receiving first data from the user equipment, the first data comprising an identification of which one of the carriers of the first type the user equipment intends to measure; and using the received first data whereby to perform said determination of the at least one carrier of the second type for which reception of communications would be interrupted by a measurement of a characteristic of the carrier of the first type by the user equipment.
3. A method according to claim 1, further comprising: receiving first data from the user equipment, the first data comprising an identification that the intended measurement would cause an interruption to reception, by the user equipment, of communications on the one or more carriers of the second type, and using the received first data whereby to perform said determination of the at least one carrier of the second type for which reception of communications would be interrupted by a measurcment of a characteristic of thc carrier of the first type by the user equipment.
4. A method according to any preceding daim, wherein the first data is received as part of a RRCConncctionSctupComplctc message.
5. A method according to any of claims 1 to 3, wherein the first data is received as part of a UECapabilitylnformation message.
6. A method according to claim 1, further comprising performing a carrier interruption determination process, the carrier interruption determination process compnsing: for each carrier of the second type, identifying whether a measurement on a said carrier of the first type would interrupt reception of the carrier of the second type on the basis of whether the carrier of the second type is within a frequency band utilised by the carrier of the first type and in dependence on whether the carrier of the first type is adjacent to one or more carriers of the second type.
7. A method according to claim 6, in which the carrier interruption determination process determines that reception of a given carrier of the second type would be interrupted by a measurement on the carrier of the first type when the given carrier of the second type is adjacent to another carrier of the second type and adjacent to the carrier of the first type, and when a plurality of said carriers of the second type and the carrier of the first type are intra-band.
8. A method according to claim 6, in which the carrier interruption determination process determines that reception of a given carrier of the second type would be interrupted by a mcasuremcnt on the carricr of thc first typc whcn thc givcn carricr of the second type is adjacent to another carrier of the second type and said another carrier of the second type is adjacent to the carrier of the first type, and when given carrier of the second type, said another carrier of the second type and the carrier of the first type arc intra-band.
9. A method according to any preceding claim, wherein the modified scheduling of communications is configured on the basis of a predetermined scheduling pattern configured at the user equipment, the predetermined scheduling pattern having a measurement slot indicating a time period in which communications are not scheduled with the user equipment on the at least one carrier of the second type.
10. A mcthod according to claim 9, whcrcin the predetcrmincd schcduling pattcrn is defined by a "DPCH Compressed Mode Info" information element stored at the network node.
11. A method according to claiim 10, wherein the predetermined scheduling pattern uses at least one of the parameters: TGPRC (Transmission Gap Pattern Repetition Count), TGSN (Transmission Gap Starting Slot Number), TGL1 (Transmission Gap Length 1), TGL2 (Transmission Gap Length 2), TGD (Transmission Gap start Distance) and TGPLI (Transmission Gap Pattern Length) indicated in the information element.
12. A method according to claim 1, wherein the network node has access to data specifying flrnctional attributcs of tim uscr cquipmcnt, and wherein tim dctermination of whether reception on a carrier of the second type would be interrupted by the intended measurement is based at least in part on the functional attributes.
13. A method of controlling communications in a communications network, the communications network comprising a user equipment capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the network node as to be inactive at the user equipment, and one or more carriers of a second type, for which the user equipment is currently configured to receive communications, the method comprising: responsive to a determination, by the user equipment, that a measurement of a characteristic of the carrier of the first type is intended by the user equipment, determining at least one carrier of the second type, for which reception by the user equipment of scheduled communications would bc intcrruptcd by the intended measurement of a characteristic of the carrier of the first type; and generating first data for output to the network node, the first data comprising an identification that the intended measurement would cause an interruption to reception, by the user equipment, of communications on said at least one carrier of the second type.
14. A method according to claim 13, wherein the first data is output to the network node as part of a RRCConncctionSctupComplctc message.
15. A method according to claim 13, wherein the first data is output to the network node as part of a UECapabilitylnformation message.
16. A method according to any of claims 13 to 15, comprising selectively using a predetermined scheduling pattern to perform the intended measurement, the predetermined scheduling pattem having a measurement slot indicating a time period in which communications are not scheduled with the network node on the at least one carrier of the second type.
17. A method according to claim 16, wherein the predetermined scheduling pattern is defined by a "DPCH Compressed Mode Info" information clement received from the network node.
18. A method according to claim 17, wherein the predetermined scheduling pattern uses at least one of the parameters: TGPRC (Transmission Gap Pattern Repetition Count), TGSN (Transmission Gap Starting Slot Number), TGL1 (Transmission Gap Length 1), TGL2 (Transmission Gap Length 2), TGD (Transmission Gap start Distance) and TGPLI (Transmission Gap Pattern Length) indicated in the information element.
19. A method of configuring a user equipment to measure a network resource in a communications network, the network resource having a carrier frequency and the user equipment being capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the network node as to be inactive at the user equipment, and at least one carrier of a second type, for which the user equipment is currently configured to receive communications, the method comprising: responsive to a determination, by the user equipment, that a measurement of a characteristic of the carrier of the first type is intended by the user equipment, determining a said carrier of the second type, for which reception by the user equipment of scheduled communications would be interrupted by the intended measurement of a characteristic of the carrier of the first type; and selectively configuring the user equipment to use a predetermined scheduling pattern to perform the measurement based on the determination of whether reception of scheduled communications on the carrier of the second type would be interrupted by the intended measurement, the predetermined scheduling pattern having a measurement slot indicating a time period in which communications are not scheduled with the network node on the carrier of the second type.
20. A method according to claim 19, wherein the predetermined scheduling pattern is defined by a "DPCH Compressed Mode Info" information element received from the network node.
21. A method according to claim 20, wherein the predetermined scheduling pattern uses at least one of the parameters: TGPRC (Transmission Gap Pattern Repetition Count), TGSN (Transmission Gap Starting Slot Number), TGL1 (Transmission Gap Length 1), TGL2 (Transmission Gap Length 2), TGD (Transmission Gap start Distance) and TGPLI (Transmission Gap Pattern Length) indicated in the information element.
22. A computer program comprising a set of instructions for execution by a computing system capable of communicating with a user equipment via a plurality of carriers, each having a different carrier frequency, wherein communications occur over at least one carrier of a first type, for which reception of communications is configured but has been indicated by the network node to be inactive at the user equipment, and at least one carrier of a second type, for which the user equipment is currently configured to receive communications, in which the set of instructions, when executed by the computing system, cause the computing system to perform the steps of determining at least one said carrier of the second type for which reception of scheduled communications, by the user equipment, would be interrupted by an intended measurement of a characteristic of the carrier of the first type by the user equipment; and selectively modifying the scheduling of communications on the or each said carrier of the second type responsive to the determination.
23. A computer program according to claim 22, wherein the set of instructions, when executed by the computing system, ifirther cause the computing system to perform the steps of: receiving first data from the user equipment, the first data comprising an identification of which one of the carriers of the first type the user equipment intends to measure; and using the received first data whereby to perform said determination of the at least one carrier of the second type for which reception of communications would be interrupted by a measurement of a characteristic of the carrier of the first type by the user equipment.
24. A computer program according to claim 22, wherein the set of instructions, when executed by the computing system, further cause the computing system to perform the steps of: receiving first data from the user equipment, the first data comprising an identification that the intended measurement would cause an interruption to reception, by the user equipment, of communications on the one or more carriers of the second type, and using the received first data whereby to perform said determination of the at least one carrier of the second type for which reception of communications would be interrupted by a measurement of a characteristic of the carrier of the first type by the user equipment.
25. A computer program according to any of claims 22 to 24, wherein the first data is received as part of a RRCConneetionSetupCompletc message.
26. A computer program according to any of claims 22 to 24, wherein the first data is received as part of a UECapabilitylnfomiation message.
27. A computer program according to claim 22, wherein the set of instructions, when executed by the computing system, further cause the computing system to perform a carrier interruption determination process, the carrier interruption determination process comprising: for each carrier of the second type, identifying whether a measurement on a said carrier of the first type would interrupt reception of the carrier of the second type on the basis of whether the carrier of the second type is within a frequency band utilised by the carrier of the first type and in dependence on whether the carrier of the first type is adjacent to one or more carriers of the second type.
28. A computer program according to claim 27, in which the carrier interruption determination process determines that reception of a given carrier of the second type would be interrupted by a measurement on the carrier of the first type when the given carrier of the second type is adjacent to another carrier of the second type and adjacent to the carrier of the first type, and when a plurality of said carriers of the second type and the carrier of the first type are intra-band.
29. A computer program according to claim 27, in which the carrier interruption dctcrmination proccss determines that reception of a given carrier of the second type would be interrupted by a measurement on the carrier of the first type when the given carrier of the second type is adjacent to another carrier of the second type and said another carrier of the second type is adjacent to the carrier of the first type, and when given carrier of the second type, said another carrier of the second type and the carrier of the first type are intra-band.
30. A computer program according to any of claims 22 to 29, wherein the modified scheduling of communications is configured on the basis ofa predetermined scheduling pattern configured at the user equipment, the predetermined scheduling pattern having a measurement slot indicating a time period in which communications are not scheduled with the user equipment on the at least one carrier of the second type.
31. A computer program according to claim 30, wherein the predetermined scheduling pattern is defined by a "DPCH Compressed Mode Info" information element stored at the computing system.
32. A computer program according to claim 31, wherein the predetermined scheduling pattern uses at least one of the parameters: TGPRC (Transmission Gap Pattern Repetition Count), TGSN (Transmission Gap Starting Slot Number), TOLl (Transmission Gap Length 1), TGL2 (Transmission Gap Length 2), TGD (Transmission Gap start Distance) and TGPL1 (Transmission Gap Pattern Length) indicated in the information element.
33. A computer program according to claim 22, wherein the computing system has access to data specifying functional attributes of the user equipment, and wherein the determination of whether reception on a carrier of the second type would be interrupted by the intended measurement is based at least in part on the functional attributes.
34. A computer program comprising a set of instructions for execution by a computing system capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the network node as to be inactive at the computing system, and one or more carriers of a second type, for which the computing system is currently configured to receive communications, in which the set of instructions, when executed by the computing system, cause the computing system to perform the steps of: responsive to a determination, by the computing system, that a measurement of a characteristic of the carrier of the first type is intended by the computing system, determining at least one carrier of the second type, for which reception by the computing system of scheduled communications would be interrupted by the intended measurement of a characteristic of the carrier of the first type; and generating first data for output to the network node, the first data comprising an identification that the intended measurement would cause an interruption to reception, by the computing system, of communications on said at least one carrier of the second type.
35. A computer program according to claim 34, wherein the first data is output to the network node as part of a RRCConnectionSetupComplete message.
36. A computer program according to claim 34, wherein the first data is output to the network node as part of a UECapabilitylnformation message.
37. A computer program according to any of claims 34 to 36, wherein the set of instructions, when executed by the computing system, further cause the computing system to selectively use a predetermined scheduling pattern to perform the intended measurement, the predetermined scheduling pattern having a measurement slot indicating a time period in which communications are not scheduled with the network node on the at least one canier of the second type.
38. A computer program according to claim 37, wherein the predetermined scheduling pattern is defined by a "DPCH Compressed Mode Info" information element received from the network node.
39. A computer program according to claim 38, wherein the predetermined scheduling pattern uses at least one of the parameters: TGPRC (Transmission Gap Pattern Repetition Count), TGSN (Transmission Gap Starting Slot Number), TOLl (Transmission Gap Length 1), TGL2 (Transmission Gap Length 2), TGD (Transmission Gap start Distance) and TGPL1 (Transmission Gap Pattern Length) indicated in the information element.
40. A computer program comprising a set of instructions for execution by a computing system configured to measure a network resource in a communications network, the network resource having a carrier frequency and the computer program being capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the network node as to be inactive at the computing system, and one or more carriers of a second type, for which the computing system is currently configured to receive communications, in which the set of instructions, when executed by the computing system, cause the computing system to perform the steps of rcsponsivc to a detcrmination, by thc computing system, that a measurement of a characteristic of the carrier of the first type is intended by the computing system, determining a said carrier of the second type, for which reception by the computing system of scheduled communications would be interrupted by the intended mcasuremcnt of a characteristic of the carrier of the first type; and selectively configuring the computing system to use a predetermined scheduling pattern to perform the measurement based on the determination of whether reception of scheduled communications on the carrier of the second type woLild be interrupted by thc intcndcd mcasurement, thc predetermined scheduling pattern having a measurement slot indicating a time period in which communications are not scheduled with the network node on the carrier of the second type.
41. A computer program according to claim 40, wherein the predetermined scheduling pattern is defined by a "DPCH Compressed Mode Info" information element received from the network node.
42. A computer program according to claim 41, wherein the predetermined scheduling pattern uses at least one of the parameters: TGPRC (Transmission Gap Pattern Repetition Count), TGSN (Transmission Gap Starting Slot Number), TGL1 (Transmission Gap Length 1), TGL2 (Transmission Gap Length 2), TGD (Transmission Gap start Distance) and TGPLI (Transmission Gap Pattern Length) indicated in the information element.
43. Apparatus for use in controlling communications in a communications network, the apparatus being capable of communicating with a user equipment via a plurality of carriers, each having a different carrier frequency, wherein communications occur over at least one carrier of a first type, for which reception of communications is configured but has been indicated by the network node to be inactive at the user equipment, and at least one carrier of a second type, for which the user equipment is currently configured to receive communications, the apparatus comprising a processing system arranged to cause the apparatus to: determine at least one said carrier of the second type for which reception of scheduled communications, by the user equipment, would be interrupted by an intended measurement of a characteristic of the carrier of the first type by the user equipment; and selectively modify the scheduling of communications on the or each said carrier of the second type responsive to the determination.
44. Apparatus according to claim 43, wherein the processing system is arranged to further cause the apparatus to: receive first data from the user equipment, the first data comprising an identification of which one of the carriers of the first type the user equipment intends to measure; and use the received first data whereby to perform said determination of the at least one carrier of the second type for which reception of communications would be interrupted by a measurement of a characteristic of the carrier of the first type by the user equipment.
45. Apparatus according to claim 43, wherein the processing system is arranged to further cause the apparatus to: receive first data from the user equipment, the first data comprising an identification that the intended measurement would cause an interruption to reception, by the user equipment, of communications on the one or more carriers of the second type, and use the received first data whereby to perform said determination of the at least one carrier of the second type for which reception of communications would be interrupted by a measurement of a characteristic of the carrier of the first type by the user equipment.
46. Apparatus according to any of claims 43 to 45, wherein the first data is received as part of a RRCConnectionSetupComplete message.
47. Apparatus according to any of claims 43 to 45, wherein thc first data is received as part of a UECapabilitylnformation message.
48. Apparatus according to claim 43, wherein the processing system is arranged to further cause the apparatus to perform a carrier interruption determination process, the carrier interruption determination process comprising: for each carrier of the second type, identifying whether a measurement on a said carrier of the first type would interrupt reception of the carrier of the second type on thc basis of whcthcr thc carricr of thc sccond type is within a frequency band utilised by the carrier of the first type and in dependence on whether the carrier of the first type is adjacent to one or more carriers of the second type.
49. Apparatus according to claim 48, in which thc carricr interruption determination process determines that reception of a given carrier of the second type would be interrupted by a measurement on the carrier of the first type when the given carrier of the second type is adjacent to another carrier of the second type and adjacent to thc carricr of thc first type, and whcn a plurality of said carricrs of thc sccond typc and the carrier of the first type are intra-band.
50. Apparatus according to claim 48, in which the carrier interruption determination process determines that reception of a given carrier of the second type would be interrupted by a measurement on the carrier of the first type when the given carrier of the second type is adjacent to another carrier of the second type and said another carrier of the second type is adjacent to the carrier of the first type, and when givcn carricr of thc sccond typc, said anothcr carricr of thc sccond typc and thc carricr of the first type are intra-band.
51. Apparatus according to any of claims 43 to 50, wherein the modified scheduling of communications is configured on thc basis of a predetcrmincd scheduling pattem configured at the user equipment, the predetermined scheduling pattern having a measurement slot indicating a time period in which communications arc not scheduled with the user equipment on the at least onc carricr of the second type.
52. Apparatus according to claim 51, wherein the predetermined scheduling pattern is defined by a "DPCH Compressed Mode Info" information element stored at the network node.
53. Apparatus according to daim 52, wherein the predetermined scheduling pattern uses at least one of the parameters: TGPRC (Transmission Gap Pattern Repetition Count), TGSN (Transmission Gap Starting Slot Number), TGLI (Transmission Gap Length 1), TGL2 (Transmission Gap Length 2), TGD (Transmission Gap start Distance) and TGPLI (Transmission Gap Pattern Length) indicated in the information element.
54. Apparatus according to claim 43, wherein the network node has access to data specifying functional attributes of the user equipment, and wherein the determination of whether reception on a carrier of the second type would be interrupted by the intended measurement is based at least in part on the functional attributes.56. User equipment for use in controlling communications in a communications network, the user equipment being capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the network node as to be inactive at the user equipment, and one or more carriers of a second type, for which the user equipment is currently configured to receive communications, the user equipment comprising a processing system arranged to cause the user equipment to: responsive to a determination, by the user equipment, that a measurement of a characteristic of the carrier of the first type is intended by the user equipment, determine at least one carrier of the second type, for which reception by the user equipment of scheduled communications would be interrupted by the intended measurement of a characteristic of the carrier of the first type; and generate first data for output to the network node, the first data comprising an identification that the intended measurement would cause an interruption to reception, by the user equipment, of communications on said at least one carrier of the second type.57. User equipment according to claim 56, wherein the first data is output to the network node as part of a RRCConncctionSctupComplctc message.58. User equipment according to claim 56, wherein the first data is output to the network node as part of a UECapabilitylnformation message.59. User equipment according to any of claims 56 to 58, wherein the processing system is arranged to further cause the user equipment to selectively use a predetermined scheduling pattem to perform the intended measurement, the predetermined scheduling pattern having a measurement slot indicating a time period in which communications are not scheduled with the network node on the at least one carrier of the second type.60. User equipment according to claim 59, wherein the predetermined scheduling pattern is defined by a "DPCH Compressed Mode Info" information element received from the network node.61. User equipment according to claim 60, wherein the predetermined scheduling pattern uses at least one of the parameters: TGPRC (Transmission Gap Pattern Repetition Count), TGSN (Transmission Gap Starting Slot Number), TGLI (Transmission Gap Length 1), TGL2 (Transmission Gap Length 2), TGD (Transmission Gap start Distance) and TGPLI (Transmission Gap Pattern Length) indicated in the information element.62. User equipment for use in measuring a network resource in a communications network, the network resource having a carrier frequency and the user equipment being capable of communicating with a network node via a plurality of carriers, each having a different carrier frequency, the plurality of carriers including a carrier of a first type, for which reception of communications is configured but is indicated by the network node as to be inactive at the user equipment, and at least one carrier of a second type, for which the user equipment is currently configured to receive communications, the user equipment comprising a processing system arranged to cause the uscr equipment to: responsive to a determination, by the user equipment, that a measurement of a characteristic of the carrier of the first type is intended by the user equipment, determine a said carrier of the second type, for which reception by the user equipment of scheduled communications would be interrupted by the intended measurement of a characteristic of the carrier of the first type; and selectively configure the user equipment to use a predetermined scheduling pattern to perform the measurement based on the determination of whether reception of scheduled communications on the carrier of the second type would be interrupted by the intended measurement, the predetermined scheduling pattern having a measurement slot indicating a time period in which communications are not scheduled with the network node on the carrier of the second type.63. User equipment according to claim 62, wherein the predetermined scheduling pattern is defined by a "DPCH Compressed Mode Info" information element received from the network node.64. User equipment according to claim 62, wherein the predetermined scheduling pattern uses at least one of the parameters: TGPRC (Transmission Gap Pattern Repetition Count), TGSN (Transmission Gap Starting Slot Number), TGLI (Transmission Gap Length 1), TGL2 (Transmission Gap Length 2), TGD (Transmission Gap start Distance) and TGPL1 (Transmission Gap Pattern Length) indicated in the information element.