KR20140031172A - Wireless apparatus and method - Google Patents

Abstract

The idle or semi-idle UE determines that the radio received signal is scrambled by a scrambling code that is not in the list of locally stored scrambling codes received from its serving network node (308), and from that scrambling code A rule is applied 310 to determine whether to decode broadcast system information transmitted by the access node. Rule 314 may be that if the scrambling code is not in the list, do not decode the broadcast system information again if the scrambling code was previously stored locally. Another rule 320 may be that if the scrambling code is not in the list, do not attempt to decode system information unless the measured signal strength for the wireless received signal is above the threshold, the threshold being an absolute threshold or received from the serving network node. It may be a threshold depending on the strength of the signal.

Description

Wireless device and method {WIRELESS APPARATUS AND METHOD}

Exemplary and non-limiting embodiments of this invention relate generally to wireless communication systems, methods, devices and computer programs. Specific embodiments relate to how user equipment (UE) / mobile terminals can limit the amount of system information they decode, especially while in an idle state or similar low power state.

The following abbreviations which may be found in the present specification and / or drawings are defined as follows:

3GPP Third Generation Partnership Project

ANR automatic neighbor relations

BSIC base transceiver station identity code

CPICH common pilot channel

DCH dedicated (physical) channel

DL downlink (Node B facing the UE)

EUTRAN Evolved UTRAN (LTE)

LTE Long Term Evolution

NCL neighbor cell list

Node B base station

RRC radio resource control

RSCP received signal code power

SI system information

SON self optimising network

TDD time division duplex

UE user equipment

UL uplink (UE faces Node B)

UTRAN Universal Terrestrial Radio Access Network

In order to handover and reselect mobile terminals / UEs from one cell / base station to another cell / base station, some wireless systems allow the UE to maintain a list of neighboring cells, for which neighboring UE the UE receives it. Measure signal power. By reporting to the serving cell for this RSCP, the network can more intelligently select when and to which cell to handover the UE.

However, the UE is mobile and has a limited power source. Idle mode is intended to conserve power of the UE but nevertheless the UE in idle mode takes measurements of neighboring cells to facilitate handover because the idle UE is still moving and may require handover. In some wireless technologies, such as UTRAN, for example to allow an operator to minimize driving tests, an idle UE takes its neighbor cell measurements and temporarily stores them, then their collected and logged measurement data. Report simultaneously to the network at some predetermined time some time later than when the earliest recorded measurements were taken. Accordingly, the UE can avoid terminating idle mode simply to report out cell identifiers and signal strengths.

There is a problem that a neighbor cell list (NCL) used by a UE for this purpose may not be up-to-date information about the current geographical location of the UE. The UE receives its NCL from its serving cell, but assuming the mobility of an idle UE, there may be neighboring cells that are no longer executable neighbors in the UE's locally stored NCL, and also executable neighbors that are not in the UE's NCL There may be a cell. The latter situation, which may arise, for example, due to pico / micro cells (eg, open or closed subscriber group cells) in a neighboring macro cell, can be handled in one of two ways. The UE may simply ignore cells not in its NCL, but this may lead to inappropriate handover and reselection to the wrong cell and / or at the wrong time. Alternatively, the UE detects and takes measurements in cells that are not in its NCL but whose RSCP is strong enough to report them, and leave the analysis of the most appropriate handover cell candidate to a power-limited network.

The trend in ongoing development of the UTRAN system (eg, 3GPP TSG-RAN WG2 Meeting # 72) is to report cells that are not in the NCL, referred to as the recorded ANR of 3GPP for brevity. Document R2-106257 entitled, for example, Discussion on UMTS ANR non CELL_DCH based approach (log approach) by Huawei and HiSilicon; Document R2-106442 entitled Method for ANR support in UTRAN by Ericsson and ST Ericsson; And document R2-106625 (all published on November 15-19, 2010; Jacksonville, U.S .; 3GPP TSG-RAN WG2 # 72) titled Configuration and Reporting for MDT based ANR by Samsung. Certain aspects of these proposals extend the concepts used for minimum drive time (MDT) measurements, whereby selected UEs take periodic measurements and report them to the network at any later UE transmission opportunity. The network then uses the measurements for routine network analysis and optimization, independent of directly managing the reporting UE.

Given the limited power of mobile terminals, measuring cells not in the NCL of the UE causes certain problems. Specifically, if a UE reports cells other than those in its NCL, it must also identify the cell global identity from which non-NCL measurements were taken in its measurement report. Most cell global identifiers IDs can be easily obtained from the system information SI broadcast by the cell itself, but to obtain this cell ID, the UE will have to decode the SI of non-NCL cells. This is not necessary for simple signal strength measurements.

During extended periods of idle time, this can be done repeatedly and as a result UE power reserves are consumed insignificantly, reducing the maximum idle / standby time that many users consider part of their cell phone purchase decision. For a shorter period of time, it is reasonable that radio channel conditions may change to the extent that some macro neighbor cells that are not in the NCL of the UE are detected. Highly dynamic radio channel conditions may cause the RSCP observed by the same UE for the same cell to go above and below the signal strength threshold for taking measurements, effectively appearing and disappearing in the UE's measurement “view”. In this case, potentially the UE will have to decode the same SI from the same cell and make duplicate write entries whenever the RSCP of the UE for that cell exceeds the threshold, because the RS will be decremented whenever the RSCP exceeds the threshold. Only after decoding will the UE know that the cell has the same global identifier as previously recorded.

Various exemplary embodiments described in detail below solve these problems to varying degrees.

According to a first aspect of the present invention, a method is provided, comprising: determining that a wireless received signal is scrambled by a scrambling code that is not in a list of locally stored scrambling codes received from a serving network node; And applying a rule from the scrambling code to determine whether to decode the broadcast system information transmitted by the access node using the scrambling code.

According to a second aspect of the present invention, there is provided an apparatus comprising a processing system, wherein the processing system causes the apparatus to be scrambling with a scrambling code in which at least a wireless received signal is not in the list of locally stored scrambling codes received from the serving network node. To determine that it is; From the scrambling code, it is configured and prepared to apply a rule that determines whether to decode the broadcast system information transmitted by the access node using the scrambling code.

The processing system may include at least one processor and at least one memory storing a computer program.

According to a third aspect of the invention, a computer program is provided, the computer program comprising: code for determining that a wireless received signal is scrambled by a scrambling code that is not in a list of locally stored scrambling codes received from a serving network node; And code for applying, from the scrambling code, a rule for determining whether to decode the broadcast system information transmitted by the access node using the scrambling code.

The computer program may be stored in a computer readable memory.

These and other embodiments and aspects are described in detail below. Further features and advantages of the invention will be apparent from the following description of the preferred embodiments of the invention, given by way of example only, with reference to the accompanying drawings.

1 shows a schematic diagram of adjacent macro cells and one pico cell, where the UE is moving towards the pico cell while under control of one serving macro cell.
FIG. 2 shows a simplified block diagram of a UE and a Node B and also a higher network node from FIG. 1, which are exemplary electronic devices suitable for use in practicing exemplary embodiments of the present invention.
3 shows a schematic logic flow diagram illustrating the operation of a method and the execution result of computer program instructions implemented in a computer readable memory, in accordance with exemplary embodiments of the present invention.

Consider FIG. 1, which illustrates an exemplary environment in which exemplary embodiments of the invention may be advantageously implemented. For the sake of brevity, the term "cell" is used interchangeably with the term "node B", where node B controls the geographic boundaries that define a cell away from neighboring cells. In Figure 1 the cell shapes and boundaries are idealized; Indeed, cell boundaries are generally not uniform and may have irregular shapes due to radio interference from structures or terrain and / or extended radio coverage from relay stations. The UE 10 under control of the serving cell A is shown. Assume that the UE is moving towards cell G and is currently in an idle state and physically near the boundary of cell A and cell G. Serving cell A previously sent to the UE an NCL that included cells B, C, D, E, G, and H in the list, since each of those cells shares a boundary with cell A (e.g. When first handing over to cell A). The UE stores this NCL in its local memory and consults it to take NCL measurements.

At its current location, the RSCP at the UE from cell C may be too weak for the UE to take and record measurements for its ANR measurement report, but this is not the only problem: UTRAN is assigned to cell C in the UE's next measurement report. From the absence of a measure for, it will be inferred that the RSCP of the UE for cell C has fallen below the measurement threshold.

For example, the problems mentioned in the background section arise when the radio conditions are quite good and the RSCP of the UE for cell F exceeds the measurement recording threshold. Since cell F is not in the UE's NCL, the UE must identify the cell from which this strong RSCP originated. Similar problems arise when there is a micro-cell such as cell J. If cells A through H are considered traditional cellular (macro) cells, cell J is a closed subscriber group (CSG) cell (e.g., home node B, university or corporate campus network), or temporarily It can be any other micro / pico cell that is organized and can be controlled by cell G (eg, form a heterogeneous network with cell G). Since cell J is a CSG or temporary, cell A may not know cell J and therefore it is not in the NCL that cell A provides its UEs, but the UE may be a member of cell J CSG (which is cell J executable) Implying a handover target).

According to an exemplary embodiment of the present invention, the UE uses the cell scrambling code to determine whether to decode the SI of the cell for ANR measurement. The UE will have one or more rules to apply if it accidentally finds a signal from a cell that is not in its NCL, which rules or rules instruct the UE to decode or not decode the SI of the non-NCL cell. At this point, power savings in the UE are realized (regardless of whether measurements taken on the signal strength of the non-NCL cell are reported in the UE's ANR measurement report) Suppose you are instructing to decode the SI of.

That is, the benefits of these teachings direct the scrambling code and rule (s) to instruct the UE to decode the SI but prevent any other decision process from refusing the UE to include measurements of non-NCL cells so that they are not reported. Even if it is obvious. More generally, in practice, it is expected that the measurements for that non-NCL cell will be reported when the UE decodes the SI.

Scrambling code as a filter for SI decoding typically relies on the general principle that scrambling codes are assigned to avoid adjacent cells using the same codes. Prior to decoding the SI, in order to avoid decoding the SI of the alternately appearing and disappearing cells, which is the problem detailed above, the UE is responsible for the cells in the NCL and also for the non-NCL cells previously decoded (and stored) by the UE. Can check their scrambling codes. In this case, the UE does not need to store the SI from the previous decoding and decode the same SI again. The scrambling code can also be used as the first filter in the decision tree on whether to decode the SI, so for example the scrambling code is not in the NCL and the UE has not yet used to decode the SI of the non-NCL cell. If so, there may be an RSCP or other signal strength threshold, different from that used for NCL cells, as the next filter for determining whether the UE decodes the SI. As an example, if the signal strength threshold for writing NCL cells is x dB, this next filter may be implemented as a signal strength threshold of (x + y) dB for recording non-NCL measurements for UL reporting.

Various embodiments summarized above are described in more detail below with respect to FIG. 3. Before describing the exemplary embodiments in detail, reference is made to FIG. 2 which illustrates a simplified block diagram of various electronic devices and apparatuses suitable for use in practicing exemplary embodiments of the present invention. In FIG. 2, a wireless network (Node B 22 and RNC 24) may be connected via a network access node, such as a base station or relay station or more specifically, Node B 22, such as a mobile terminal or UE 20. It is adapted to communicate with the device via a wireless link 21. The network may include a network control element RNC 24, which provides a connection with additional networks (eg, public switched telephone network PSTN and / or data communication network / internet).

The UE 20 is provided with processing means such as at least one data processor (DP) 20A and at least one computer readable memory (MEM) 20B that stores at least one computer program (PROG) 20C. Storage means, communication means such as transmitter TX 20D and receiver RX 20E for two-way wireless communication with Node B 22 via one or more antennas 20F. The MEM 20B also includes the NCL received from the Node B 22 by the UE 20 at 20G, the record data stored by the UE 20 until it is measured and transmitted in the ANR measurement report, and mentioned above and below. A rule or rules is stored for determining whether to decode the SI of a non-NDL cell, as described further below.

Node B 22 also includes processing means such as at least one data processor (DP) 22A, at least one computer readable memory (MEM) 22B that stores at least one computer program (PROG) 22C, and Same storage means, and communication means such as transmitter TX 22D and receiver RX 22E for two-way wireless communication with UE 20 via one or more antennas 22F. Data and / or control path 25 connecting Node B 22 to RNC 24, and another data and / or data path connecting Node B 22 to other Node Bs / access nodes. There is 23.

Similarly, the RNC 24 stores at least one computer readable memory (MEM) 24B which stores processing means such as at least one data processor (DP) 24A and at least one computer program (PROG) 24C. Storage means, and communication means such as a modem 24H for two-way wireless communication with the Node B 22 via the data / control path 25. Although not specifically illustrated for the UE 20 or the Node B 22, the devices may also be embedded in the RF front end chip in the devices 20, 22 as part of their wireless communication means and also TX It is assumed to include modems with (20D / 22D) and RX (20E / 22E).

At least one of the PROGs 20C in the UE 20, when executed by the associated DP 20A, enables the device to operate in accordance with exemplary embodiments of the present invention, as described in more detail below. It is assumed to contain program instructions. Node B 22 and RNC 24 may also have software that implements certain aspects of these teachings to process and analyze ANR measurement reports that it receives from the UE by knowing what rules the UE is using. Can be. In this regard, exemplary embodiments of the present invention may be implemented at least in part by MEMs 20B, 22B executable by DP 20A of UE 20 and / or by DP 22A of Node B 22. It may be implemented by stored computer software, or by hardware, or by a combination of tangibly stored software and hardware (and tangibly stored firmware). Electronic devices that implement these aspects of the present invention need not be the entire UE 20 or Node B 22, and exemplary embodiments may include one or more components, such as the typed stored software, hardware, firmware, and DP described above, Or by a system-on-chip SOC or application specific integrated circuit ASIC.

In general, various embodiments of a UE 20 include, but are not limited to, cellular telephones; And personal portable digital devices having wireless communication capabilities including, but not limited to, laptop / palmtop / tablet computers, digital cameras and music devices, and Internet information devices.

Various embodiments of computer readable MEMs 20B and 22B include semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, removable memory, disk memory, flash memory, DRAM, SRAM, EEPROM, and the like. It includes any data storage technology type suitable for the local technology environment, including but not limited to. Various embodiments of DPs 20A and 22A include, but are not limited to, general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), and multi-core processors.

Referring now to FIG. 3, more specific exemplary embodiments are described in terms of the UE 20. Blocks 302, 304, and 306 set up an environment for implementation in blocks 308 and 310 that use the scrambling code to determine whether to decode the SI.

At block 302 the UE receives from the serving cell / node B an NCL including a list of frequencies and scrambling codes or physical cell identifiers or BSIC for neighbor cells in the NCL. By way of example, Node B may send it to UE 20 as soon as it registers with a cell after handover to another cell or after initial access via a random access channel (RACH). Note that the neighbor cells may or may not be the same radio access technology as the serving cell. By way of example, the serving cell may be a UTRAN cell and various ones of the neighbor cells may be UTRAN, EUTRAN, GERAN, GSM or some other radio technology. The UE 20 measures all possible cells to assess the need for reselection.

At block 304 the UE is in an idle or semi-idle operational state. Details about idle and semi-idle states are mentioned below for the UTRAN system, but other systems may use different names for idle and semi-idle states. Specifically, the idle and semi-idle states in the UTRAN include the CELL_FACH state in which the UE continuously monitors the forward access channel (FACH) in the DL as well as the idle state; A CELL_PCH state in which the UE selects a paging channel (PCH) through an algorithm and monitors it via a paging indicator channel (PICH) using its discontinuous reception cycle (DRX); And a URA_PCH state (URA = user registration area) similar to the CELL_PCH state except that the network knows the location of the UE up to the level of the URA registration area rather than to the cell level as in the CELL_PCH state. All of these states are characterized by performing autonomous reselection when the UE moves between cells but not handover under network control. If a DCH is assigned to the UE 20, the UE is no longer in an idle or semi-idle operating state.

While in the idle or semi-idle state, at block 306 the UE 20 scans the list of frequencies in the NCL currently stored locally in the memory of the current UE using all possible UTRA scrambling codes. For the reasons mentioned below, the serving cell may transmit a list of scrambling codes (herein referred to as an exclusion list) that the UE 20 should not check. In this case, the UE 20 scans all frequencies in the locally stored list using all possible UTRA scrambling codes except the scrambling codes in its exclusion list of the scrambling codes received from the serving node in block 306.

In block 308 the UE 20 determines that the wireless received signal is scrambled by a scrambling code that is not in the NCL list of locally stored scrambling codes received from the serving cell / serving network node. In block 310 the UE 20 applies a rule (which may in fact be one or more rules) determining whether to decode the broadcast system information sent by the access node using the scrambling code from the scrambling code. The term access node that broadcasts an SI using its scrambling code is used to distinguish it from the serving cell / serving network node that transmitted the NCL of block 308. As a non-limiting example, the access node may be a macro-cell base station, home node B, or an access node for a CSG or pico / micro cell. Some such exemplary rules are described in detail in blocks 314 and 320 below.

Block 312 provides additional actions that the UE 20 can take if the determination of block 308 is to decode broadcast system information. In this case, the UE 20 decodes the broadcast system information to determine the identifier of the network cell that transmitted the radio reception signal, and the uplink measurement report including an indication of the signal strength for the radio reception signal and an identifier of the access node. Or UE 20 writes the decoded information to its memory for later reporting. Block 312 also provides for the UE to both record the signal strength indication and identifier in memory and transmit in the UL measurement report.

Block 314 provides one exemplary rule for block 306, that is, if the scrambling code is not in a locally stored list received from a serving node, then the scrambling code is locally located from a previous instance that decodes system information. If so, don't decode the broadcast system information again. Blocks 316 and 318 provide additional details for implementing this rule. Specifically, the rule not to decode the broadcast system information remains valid until there is a change in the serving cell according to block 316, or at block 318 until it has passed a fixed time period (e.g. The SI for the serving cell remains valid (until 10 minutes have elapsed since the first decoding). This rule assumes that the scrambling codes are properly planned and assigned in that area, so it applies to any micro / pico and macro target cell. If there are unplanned networks (eg, a CSG / femto deployment such as cell J of FIG. 1), different UEs may report different CSG cells with the same scrambling code. An advantage of the fixed time period of block 318 is that different UEs can share the burden of ANR, and one UE does not have to provide all the information to the network.

Block 320 provides another exemplary rule for block 306, i.e., the rule indicates that if the scrambling code is not in the locally stored list received from the serving node, the system is measured if the measured signal strength for the wireless received signal is not higher than the threshold. Do not try to decode the information. In this case, the threshold may be an absolute threshold or a threshold that depends on the strength of the signal received from the serving node.

The absolute threshold may be implemented such that the UE should not attempt to decode the SI if the cell CPICH Ec / Io or RSCP is worse by some fixed dimension (x dB) than the absolute threshold. When performing ANR this is very beneficial for optimizing for the connection mode neighbor lists used for handover, since handover decisions are often based on absolute thresholds. If absolute priority based reselection is used in the network, this may also be beneficial in determining neighbor lists for idle mode operation.

In the case of the relative signal strength threshold, the signal strength may be, for example, the cell CPICH Ec / Io (ratio of received pilot energy Ec to total received energy or total power spectral density Io), and the measured RSCP is no greater than the measurement of the serving cell. It may be less than a fixed dimension (in dB) or better than some fixed dimension than the measurement of the serving cell. This may not need to establish a weak cell and neighbor relationship (intentional selection of the operator) and also the decoding of the SI block may fail or take noticeably longer than in the case of neighboring cells of more normal intensity (thus a greater battery impact). This is an efficient rule in that it is more likely. From the point of view of the network, it is more advantageous for these neighboring cells to be decoded and recorded by different UEs. In particular, when optimizing for an idle mode neighbor list (used for cell reselection / handover), the neighbor relationship is better evaluated if the cell is evaluated according to reselection rules, which may be based on thresholds related to the serving cell. Most useful.

In various implementations, the threshold (s) mentioned at block 318 for decoding can be indicated as part of the ANR configuration by the UTRAN network (eg, at block 302) or it is hard-coded to a specification that governs the procedure. It may be hard coded or it may be left to the UE implementation to determine the thresholds.

It is important to note that sometimes detectable cells are intentionally missing from the NCL by network operators, such as, for example, when physically neighboring cells are in national / political boundary regions and belong to different network operators. . In this case, in an exemplary embodiment, the serving cell indicates a list or range of scrambling codes that the UEs expect not to record when detected. Both absolute thresholds and thresholds related to the current serving cell can be considered in the exclusion record list.

An exemplary practical embodiment is to retrieve all possible UTRA scrambling codes while the NCL the UE receives from the serving cell has scrambling codes and frequencies for the cells in the NCL and the UE is in idle mode. This non-NCL scrambling code search may be performed at a reduced rate compared to the search for cells included in the list of NCLs. The UE may perform this reduced speed search for all frequencies included in the NCL. If a cell that is not among those in the NCL list is detected, it is determined whether to decode the SI based on the scrambling code and rules, exemplary rules are described in detail with respect to FIG. 3.

One technical effect of these exemplary embodiments is that UE battery life is extended. The operating cost is that in some cases there may be less information about the network in individual UE records, but the exemplary rules are aimed to minimize this effect. For example, the same scrambling code in a short time / same geographic area will likely be likely to provide only duplicate information. This is also alleviated in that multiple UEs can be used for ANR.

3 is a logic flow diagram that may be considered to illustrate the operation of a method, and the results of execution of a computer program stored in a computer readable memory, and a particular manner in which components of an electronic device are configured to operate the electronic device. The various blocks shown in FIG. 3 may also be considered particular results of a plurality of connected logic circuit elements configured to perform associated function (s), or strings of computer program code stored in memory.

Such blocks and the functions they represent are non-limiting examples, and can be implemented in various components such as integrated circuit chips and modules, and exemplary embodiments of the present invention can be realized in an apparatus implemented as an integrated circuit. An integrated circuit, or circuits, for implementing at least one or more of a data processor or data processors, a digital signal processor or processors, a baseband circuit, and a radio frequency circuit that may be configured to operate in accordance with exemplary embodiments of the present invention. May include circuitry (as well as firmware).

Those skilled in the relevant art will apparently appreciate various modifications and adaptations to the foregoing exemplary embodiments of the invention in view of the foregoing description. While exemplary embodiments have been described above in the context of UTRAN systems, exemplary embodiments of the invention are not limited to being used only in this one particular type of wireless communication system, and they are for example with GERAN and GSM and others. It should be appreciated that it can be advantageously used in other wireless communication systems as well.

Moreover, the various names used in the description (eg, NCL, various idle states and names of channels, etc.) are by no means intended to be limiting, because different radio technologies may use different terms for similar concepts. Because. Particular UTRAN terms are used to provide a more specific set of examples to illustrate the concepts of the invention presented herein. Some of the various features of the non-limiting embodiments can be advantageously used without the corresponding use of other described features. Thus, the foregoing description should not be considered as limiting the principles, teachings and exemplary embodiments of this invention, but should be considered as merely illustrative thereof.

Claims (20)

Determining that the wireless received signal is scrambled by a scrambling code that is not in the list of scrambling codes received from the serving network node; And
Applying a rule from the scrambling code to determine whether to decode broadcast system information transmitted by an access node using the scrambling code
≪ / RTI > The method of claim 1, wherein if the determination is to decode the broadcast system information, the method further comprises:
Decoding the broadcast system information to determine an identity of the access node that has transmitted the wireless received signal; and
Performing at least one of an indication of signal strength for the wireless received signal and storing an identifier of the access node in a memory and transmitting in an uplink measurement report. 3. The method of claim 1 or 2, wherein determining that the radio received signal is scrambled by the scrambling code scans all frequencies in a locally stored list using all possible universal terrestrial radio access (UTRA) scrambling codes. Method comprising the steps of: The method of claim 1 or 2, wherein determining that the radio received signal is scrambled by the scrambling code comprises all but the scrambling codes in an exclusion list of scrambling codes received from the serving network node. Scanning all frequencies in a locally stored list using possible universal terrestrial radio access (UTRA) scrambling codes. The method according to any one of claims 1 to 4, wherein the rule is
If the scrambling code is not in a locally stored list received from the serving network node, then do not decode the broadcast system information again if the scrambling code is stored locally from a previous instance of decoding the system information. How to. 6. The method of claim 5, wherein the rule not to decode the broadcast system information remains valid until at least one of a fixed time period has elapsed and there is a change in serving cell. The method according to any one of claims 1 to 6, wherein the rule is
If the scrambling code is not in a locally stored list received from the serving network node, do not attempt to decode the system information unless the measured signal strength for the wireless received signal is higher than a threshold;
The threshold is one of an absolute threshold and a threshold that depends on the strength of a signal received from the serving network node. The method of claim 1, wherein the method is performed by user equipment. An apparatus comprising a processing system, the processing system causing the apparatus to at least:
Determine that the wireless received signal is scrambled by a scrambling code that is not in a locally stored list of scrambling codes received from the serving network node;
And from the scrambling code, apply and configure a rule to determine whether to decode broadcast system information transmitted by an access node using the scrambling code. 10. The system of claim 9, wherein if the determination is to decode the broadcast system information, the processing system causes the apparatus to at least:
Decode the broadcast system information to determine an identity of the access node that has transmitted the radio received signal,
And configured to perform at least one of an indication of signal strength for the wireless received signal and storing the identifier of the access node in at least one memory and transmitting in an uplink measurement report. The apparatus of claim 9 or 10, wherein the processing system causes the apparatus to scan all frequencies in the locally stored list using all possible universal terrestrial radio access (UTRA) scrambling codes. And configured to cause a wireless received signal to be determined to be scrambled by the scrambling code. 11. The method according to claim 9 or 10, wherein the processing system causes the apparatus to scrambling all possible universal terrestrial radio access (UTRA) except for scrambling codes in an exclusion list of scrambling codes received from the serving network node. Configured and prepared to cause the apparatus to determine that the radio received signal is scrambled by the scrambling code by having to scan all frequencies in the locally stored list using codes. The method according to any one of claims 9 to 12, wherein the rule is
If the scrambling code is not in the locally stored list received from the serving network node, then do not decode the broadcast system information again if the scrambling code is stored locally from a previous instance of decoding the system information. Containing device. 14. The apparatus of claim 13, wherein the rule not to decode the broadcast system information remains valid until at least one of a fixed time period has elapsed and there is a change in serving cell. The method according to any one of claims 9 to 14, wherein the rule is
If the scrambling code is not in the locally stored list received from the serving network node, do not attempt to decode the system information unless the measured signal strength for the wireless received signal is not above a threshold;
The threshold is one of an absolute threshold and a threshold that depends on the strength of a signal received from the serving network node. 16. The device of any one of claims 9-15, wherein the device comprises user equipment. Code for determining that a wireless received signal is scrambled by a scrambling code that is not in a locally stored list of scrambling codes received from a serving network node; And
Code for applying a rule for determining, from the scrambling code, whether to decode broadcast system information transmitted by an access node using the scrambling code.
Computer program comprising a. 18. The computer program of claim 17 wherein the determination is to decode the broadcast system information.
Code for decoding the broadcast system information to determine an identity of the access node that has transmitted the radio received signal, and
And code for performing at least one of an indication of signal strength for the wireless received signal and storing the access node's identifier in a computer readable memory and transmitting in an uplink measurement report. 19. The method of claim 17 or 18, wherein the rule is
If the scrambling code is not in the locally stored list received from the serving network node, then do not decode the broadcast system information again if the scrambling code is stored locally from a previous instance of decoding the system information. Computer program included. 20. The method of any one of claims 17 to 19, wherein the rule is
If the scrambling code is not in the locally stored list received from the serving network node, do not attempt to decode the system information unless the measured signal strength for the wireless received signal is not above a threshold;
The threshold is one of an absolute threshold and a threshold that depends on the strength of a signal received from the serving network node.

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