HK1170884B - Method and apparatus for detecting and measuring for home node-bs - Google Patents

Description

Method and apparatus for detection and measurement for home node bs

Cross Reference to Related Applications

The present application claims the benefit of the following applications: united states provisional application No. 61/218,824 filed on 19/6/2009; united states provisional application No. 61/248,003 filed on 2/10/2009; united states provisional application No. 61/250,255 filed on 9/10/2009; filed on 2/10/2009, provisional application No. 61/247,968, which is hereby incorporated by reference as if set forth in its entirety herein.

Technical Field

The present invention relates to wireless communications.

Background

Home node bs (hnbs) for Universal Mobile Telecommunications System (UMTS) and home evolved node bs (henbs) (collectively "home node bs (hnbs)") for Long Term Evolution (LTE) have been introduced in the eighth edition of the third generation partnership project (3GPP) standards, for example, for the purpose of improving cellular coverage and overall system throughput. HNBs are physical devices (e.g., Access Points (APs) similar to Wireless Local Area Networks (WLANs)) that provide access to UMTS and/or LTE services over very small service areas (or cells), such as private homes, small offices, and coffee shops. Access to the HNB is restricted to a smaller, more refined group of users known as a Closed Subscriber Group (CSG) than to WLAN APs that are typically accessible to wireless devices within their range. However, similar to WLAN APs, HNBs connect their user wireless devices to the HNB operator core network. For HNBs, a connection may be established using, for example, an internet connection, such as a Digital Subscriber Line (DSL). For example, a coffee shop owner (or user) may choose to deploy an HNB in his or her coffee shop to provide a customer (CSG in this example) with a stronger wireless connection than would be available in the shop when not deployed. Due to such use within a small service area, HNBs may be densely deployed and accordingly located within the coverage area of one or more macro node bs.

To enable certain functions of a wireless device or wireless transmit/receive unit (WTRU), such as Handover (HO) between network nodes, it may be necessary for the WTRU to perform measurements, for example, on other frequencies or systems. To perform these measurements, the WTRU may require gaps.

The inter-frequency measurement reporting rule does not include a scenario that may be more preferable for a WTRU to switch from a macro cell frequency to an HNB frequency even though the quality of the macro cell frequency is still acceptable. When a WTRU is located at one or more cell edges and needs to switch to another frequency, the network typically configures the WTRU with compressed mode with gaps to measure the other frequency.

Inter-frequency measurement reporting rules are rarely applicable to HNBs, such as HNBs in private homes that may be deployed anywhere in the macro cell coverage area (as described above). However, one user may prefer to handover from a macro cell to an HNB even if the quality of the frequency serving the macro cell is above a predetermined threshold. In order for a WTRU to handover from a macro cell to an HNB, the network may need to configure the compressed mode for the user's WTRU to detect the HNB Primary Scrambling Code (PSC) (applicable to UMTS HNBs) or the Physical Cell Identity (PCI) (applicable to LTE HNBs) on other frequencies.

Disclosure of Invention

Methods and apparatus for a wireless transmit/receive unit (WTRU) to detect and perform measurements on a frequency and other systems with respect to a Home Node B (HNB) and a home evolved node B (h (e) NB) (collectively, "HNB"). The method can include generating and transmitting a request for a measurement configuration including a request for a gap allocation for Primary Scrambling Code (PSC) or Physical Cell Identity (PCI) for detecting and measuring at least one frequency or radio access technology of a target HNB. The request may be in response to the WTRU entering an HNB cell for which the WTRU has stored its feature (fingerprint) information and for which its Closed Subscriber Group (CSG) ID is in the WTRU's white list. In addition, a method for releasing a measurement configuration including any gaps is described. The network may configure the WTRU to make measurements on the requested frequency or RAT in response to the proximity/proximity report/request.

Drawings

The invention will be understood in more detail from the following description, given by way of example and understood in conjunction with the accompanying drawings, in which:

fig. 1 is an example of a Home Node B (HNB) or home (evolved) node B (h (e) NB) (collectively, HNBs) deployed in a wireless communication system;

FIG. 2 is an example of a wireless communication system that may be used with the system of FIG. 1;

figure 3 is an exemplary functional block diagram of a wireless transmit/receive unit (WTRU) and a node-B of the wireless communication system of figure 2;

FIG. 4 is an example of another wireless communication system that may be used with the system of FIG. 1;

figure 5 is an exemplary functional block diagram of a WTRU and a node-B of the wireless communication system of figure 4;

figure 6 is an exemplary functional block diagram of another WTRU of the wireless communication system of figures 2 and 4;

figure 7 is an exemplary method of a WTRU entering a cell of an HNB;

figure 8 is an exemplary method of a WTRU away from a cell of an HNB.

Detailed Description

As referred to hereafter, the term "wireless transmit/receive unit (WTRU)" includes but is not limited to a User Equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a Personal Digital Assistant (PDA), a computer, or any other type of device capable of operating in a wireless environment. As referred to hereafter, the term "base station" includes, but is not limited to, a node B, a site controller, an Access Point (AP), or any other type of interfacing device capable of operating in a wireless environment. Home Node Bs (HNBs) and home evolved node bs (henbs) (collectively HNBs) may be WTRUs, base stations, or a combination thereof.

HNBs have been introduced in Long Term Evolution (LTE) and Universal Mobile Telecommunications System (UMTS), respectively, as part of an effort to provide improved spectral efficiency, reduced latency, and better radio resource utilization leading to faster user experiences, richer applications, and lower service costs. The HNB provides users with access to network services over a very small service area, such as a home or small office. A user (e.g., an individual or an organization) may deploy an HNB over an area where such service is desired. In general, an HNB cell may be any cell that broadcasts a Closed Subscriber Group (CSG) ID. The HNB cell may refer to a CSG cell or a hybrid cell. A CSG cell refers to a defined area over which radio coverage provided by an HNB can only be accessed by an authorized group of users through a CSG ID to use the service of the cell. A hybrid cell refers to a cell that has a defined area over which radio coverage provided by the HNB corresponds to a CSG ID, but can be accessed by non-member WTRUs. The HNB may be deployed on the same carrier as an open or macro base station, or may be deployed on a dedicated carrier. In general, a macro cell refers to a defined area over which radio coverage is provided by a base station (also referred to as a normal or open cell). In some cases, a macro cell may also refer to a CSG cell.

Although the terms used herein correspond substantially to Universal Mobile Telecommunications System (UMTS) technology, the concepts described herein may be applied to other wireless technologies, such as LTE. Thus, for example, if the term Primary Scrambling Code (PSC) is used herein, it can be considered equivalent to Physical Cell Identity (PCI) in LTE. Further, the terms compressed mode gap and measurement gap may be used interchangeably herein and are collectively referred to hereinafter as "gap". These "gaps" refer to the gaps that may be required for the WTRU to perform measurements on at least one frequency and other systems. Further, these gaps may correspond to compressed mode gaps for UMTS and measurement gaps for LTE. Still further, the term Cell Global Identity (CGI) may refer to the LTE CGI as well as the UMTS Cell Identity (CI) broadcasted in the system information of the cell.

To enable certain functionality of a wireless device or wireless transmit/receive unit (WTRU), such as Handover (HO) between network nodes, it may be necessary for the WTRU to perform measurements, such as measurements of cells on a certain frequency or system. To perform these measurements, the WTRU may need measurement configurations, which may include a pattern of: during this mode, the WTRU is allowed to discontinue reception on its serving cell in order to perform measurements on the same or other frequencies and other Radio Access Technologies (RATs). This mode may correspond to a compressed mode gap in UMTS or a measurement gap in LTE, and will be referred to as a "gap" hereinafter.

The measurement configuration may include many measurement types, such as inter-frequency measurements, intra-frequency measurements, and inter-RAT measurements to assist in network handover. For both UMTS and LTE, these measurement types are configured by the network, and if the WTRU is configured with these events, the WTRU may measure on a certain frequency or Radio Access Technology (RAT). In some cases, the network must configure the WTRU with gaps in order to make measurements on at least one frequency or RAT. Some inter-frequency measurement reporting events specified in the 3GPP standards for UMTS and LTE include (assuming a single radio implementation): event 2a ("optimum frequency change"); event 2b ("estimated quality of currently used frequencies is below a certain threshold and estimated quality of unused frequencies is above a certain threshold"); event 2c ("estimated quality of unused frequencies above a certain threshold"); event 2d ("estimated quality of currently used frequency below some threshold"); event 2e ("estimated quality of unused frequencies below a certain threshold"); and event 2f ("estimated quality of currently used frequency is above a certain threshold"). Measurements that require criteria to evaluate these events may require the WTRU to be configured with gaps.

Measurements on at least one frequency or RAT may be power consuming and may result in some service degradation when gaps are needed to make the measurements. Thus, by default, the wireless device may not be configured to make measurements on at least one frequency or RAT. The network may rely on the receipt of a measurement report (e.g., event 2D) indicating that the quality of the currently used frequency is below a threshold. In this case, the network may then configure the WTRU to start measuring on one frequency or RAT, and may further configure the WTRU with gaps.

For LTE, the following events may be configured for inter-frequency measurement types: event a3 (neighbor becomes better than serving by an offset); event a4 (neighbor becomes better than absolute threshold); and event a5 (service becomes worse than absolute threshold 1 and neighbor becomes better than another absolute threshold 2). In a typical single radio implementation, the configuration gap is typically required to ensure that the WTRU is given a minimum time to perform the measurements.

Existing measurement reporting rules do not include the following scenarios: in this scenario the WTRU may preferably switch from the macrocell frequency to the HNB frequency even though the quality of the macrocell frequency is still acceptable. The network typically configures the WTRU to make measurements on one or more cells, frequencies, or RATs when the WTRU is at the border of the other cell, frequency, or RAT and needs to handover to the other cell, frequency, or RAT. Assuming that the network is unaware of the deployment or whether the WTRU is allowed to connect to an HNB under macro cell coverage for an HNB, the network may not know when to configure the WTRU to perform HNB measurements on at least one frequency or RAT.

Methods and apparatus are disclosed herein that facilitate a wireless transmit/receive unit (WTRU) detecting an HNB, measuring a frequency or RAT with respect to the HNB, and releasing a measurement configuration that may include gaps. The method can include generating and sending a request for a measurement configuration, which can include a request for a gap allocation for PSC or PCI to detect and measure a target HNB for at least one frequency or RAT. The request may be in response to the WTRU entering the vicinity or proximity of an HNB cell for which the WTRU has stored its characteristic information (i.e., autonomous search functionality) and for which the Closed Subscriber Group (CSG) ID is in the WTRU's whitelist. This may be determined in the WTRU by using WTRU-specific feature information. The WTRU whitelist includes CSG IDs of HNBs that the WTRU may be allowed to access. The request sent by the WTRU may include frequency, RAT, cell identity, and other similar information. The network may then configure the WTRU to measure the requested frequency or RAT in response to the proximity/proximity report/request. In addition, a method of releasing a measurement configuration including a gap is described. The request to release the measurement configuration may be in response to the WTRU leaving the vicinity of the HNB cell whose CSG ID is in the WTRU's whitelist according to the stored characteristic information (i.e., autonomous search function).

It will be appreciated that the methods disclosed herein are applicable and may also be configured for inter-frequency, inter-Radio Access Technology (RAT), and intra-frequency measurements for HNB cells or frequencies.

Fig. 1 shows one example of HNB deployment in a wireless communication system 100. The wireless communication system 100 includes an LTE open cell 105, a 3GPP system cell 110, a higher network node (e.g., gateway) 115, and/or a Mobility Management Entity (MME)/serving General Packet Radio Service (GPRS) support node (SGSN) 120. The higher network node 115 is responsible for coordinating the operation of several HNBs 125A, 125B and 125C. Alternatively, the MME/SGSN 120 may be responsible for coordinating the operation of several HNBs 125A, 125B, and 125C. The MME is LTE equivalent to SGSN/GGSN of 3G/2G. The relationship between LTE open cells 105 and other 3GPP systems 110, such as WCDMA/global system for mobile communications (GSM), is that there may be some areas covered by the superposition of these two technologies. Similar to the simultaneous coverage of GSM and WCDMA technologies. The higher network node 115 may be a gateway function that is connected with the MME/SGSN 120. As a gateway, the higher network node 115 may act as a separate open cell towards the MME/SGSN 120 when supporting several small home cells or CSG cells.

Figure 2 is a block diagram of an exemplary wireless communication system 200, which wireless communication system 200 and system 100 work together and may include a plurality of WTRUs 210, a node B220, a Controlling Radio Network Controller (CRNC)230, a Serving Radio Network Controller (SRNC)240, and a core network 250. The node B220 and the CRNC 230 may be collectively referred to as a Universal Terrestrial Radio Access Network (UTRAN) 235.

The WTRU210 shown in fig. 2 communicates with a node B220, the node B220 communicating with a CRNC 230 and an SRNC 240. Although the exemplary system 200 shown in figure 2 includes three WTRUs 210, one node B220, one CRNC 230, and one SRNC 240, any combination of wireless and wired devices may be included in the wireless communication system.

Figure 3 is a functional block diagram 300 of one WTRU210 and node-B220 of the example wireless communication system 200 of figure 2. In general, the WTRU210 shown in fig. 3 is in communication with the node B220, and both the WTRU210 and the node B220 are configured to detect HNBs, receive configuration information, make measurements on at least one frequency or RAT with respect to HNBs, and release measurement configurations, possibly including gaps, with respect to WTRUs entering or leaving HNB cells. In the UMTS architecture, the SRNC sends configuration information and processes the measurements.

In addition to the components that may be found in a typical WTRU, the exemplary WTRU210 includes a processor 315, a receiver 316, a transmitter 317, a memory (not shown), and an antenna 318. The memory may be provided for storing software that may include, for example, an operating system, application programs, and other such software. The processor 315 is configured to detect, alone or in conjunction with software, an HNB, receive configuration information, make measurements on at least one frequency or RAT of the HNB, and release measurement configurations including gaps for WTRUs entering or leaving the HNB cell. The receiver 316 and transmitter 317 are in communication with the processor 315. The antenna 318 is in communication with both the receiver 316 and the transmitter 317 to facilitate the transmission and reception of wireless data.

In addition to the components that may be found in a typical base station, node B220 includes a processor 325, a receiver 326, a transmitter 327, and an antenna 328. The processor 325 may be configured to, alone or in conjunction with software, detect HNBs, detect proximity/proximity to entering or leaving HNBs, receive configuration information that may include gaps, make measurements on at least one frequency or RAT of HNBs, and release measurement configurations that may include gaps for WTRUs in proximity/proximity to entering or leaving HNB cells. The receiver 326 and the transmitter 327 are in communication with the processor 325. The antenna 328 is in communication with both the receiver 326 and the transmitter 327 to facilitate the transmission and reception of wireless data. In the UMTS architecture, the SRNC sends configuration information and processes measurements.

Fig. 4 shows a Long Term Evolution (LTE) wireless communication system/access network 400, which may operate in system 100 and may include an evolved-universal terrestrial radio access network (E-UTRAN) 405. The E-UTRAN 405 includes a number of evolved node Bs (eNBs) 420. The WTRU410 communicates with the eNB 420. The enbs 420 are connected to each other using an X2 interface. Each eNB 420 is connected to a Mobility Management Entity (MME)/serving gateway (S-GW)430 through an S1 interface. Although a single WTRU410 and three enbs 420 are shown in fig. 4, it should be apparent that any combination of wireless and wired devices may be included in the wireless communication system access network 400.

Figure 5 is an exemplary block diagram of an LTE wireless communication system 500 including a WTRU410, an eNB 420, and an MME/S-GW 430. As shown in fig. 5, the WTRU410, eNB 420, and MME/S-GW430 are configured to detect HNBs, detect entering or leaving the vicinity/proximity of HNBs, receive configuration information that may include gaps, make measurements on at least one frequency or RAT on HNBs, and release measurement configurations that may include gaps for WTRUs entering or leaving the vicinity/proximity of HNB cells.

In addition to the components that may be found in a typical WTRU, the WTRU410 includes a processor 516 with an optional linked memory 522, at least one transceiver 514, an optional battery 520, and an antenna 518. The processor 516 is configured to detect an HNB, detect a vicinity/proximity to or to enter an HNB, receive configuration information that may include gaps, make measurements on at least one frequency or RAT with respect to the HNB, and release measurement configurations that may include gaps with respect to WTRUs that enter or leave the vicinity/proximity of the HNB cell. The transceiver 514 is in communication with the processor 516 and the antenna 518 to facilitate the transmission and reception of wireless communications. If the battery 520 is used in the WTRU410, it powers the transceiver 514 and the processor 516.

In addition to the components that may be found in a typical eNB, the eNB 420 includes a processor 517 with an optional linked memory 515, a transceiver 519, and an antenna 521. The processor 517 is configured to detect for HNBs, detect entering or leaving proximity/vicinity of HNBs, receive configuration information that may include gaps, make measurements on at least one frequency or RAT with respect to HNBs, and release measurement configurations that may include gaps with respect to WTRUs entering or leaving proximity/vicinity of HNB cells. The transceiver 519 is in communication with the processor 517 and the antenna 521 to facilitate the transmission and reception of wireless communications. The eNB 520 is connected to a mobility management entity/serving gateway (MME/S-GW)530 comprising a processor 533 with an optional link memory 534.

Figure 6 is an exemplary block diagram of a WTRU 600 configured in accordance with embodiments disclosed herein. In addition to the components that may be found in a typical WTRU, the WTRU 600 includes an antenna 605, a transmitter 610, a receiver 615, a processor 620, and a Universal Subscriber Identity Module (USIM) (or LTE equivalent) 625. The receiver 615 is configured to receive broadcasts from cells including cell IDs through the antenna 605. The processor 620 is electrically connected to the transmitter 610, the receiver 615, and the USIM (or LTE equivalent) 625. The processor 620 is configured to detect an HNB, detect entering or leaving proximity/vicinity of an HNB, receive configuration information that may contain gaps, measure at least one frequency or RAT with respect to an HNB, and release measurement configurations that may include gaps with respect to WTRUs entering or leaving proximity/vicinity of an HNB cell.

Various embodiments are described herein for detecting an HNB, receiving configuration information, making measurements on at least one frequency or RAT of the HNB, and releasing a measurement configuration, which may include a gap, for a WTRU entering or leaving an HNB cell. These embodiments may include some methods: for example, the WTRU may use the method to request a measurement configuration that may include a gap allocation request so that the WTRU may detect the PSC or PCI of the HNB at the neighbor and/or measure its PSC or PCI on other frequencies. In addition to any gaps, embodiments are also provided for releasing the measurement configuration.

Two different scenarios may be considered with respect to various embodiments. In the first case, the WTRU accesses a certain HNB for the first time. In the second case, the WTRU next encounters the same HNB (after the initial encounter). In the second case, the WTRU has stored the characteristic information (e.g., CSG in WTRU whitelist) identifying the approximate location of the allowed HNB and may use it to determine whether the WTRU is located in the vicinity of the allowed HNB. Based on the determination, the WTRU may know whether to make measurements on at least one frequency or RAT. Herein, the terms near and adjacent may be used interchangeably.

In one embodiment, when such a determination is made, the WTRU may send a request (e.g., a report) to the network informing the network of the proximity of this HNB. This may be used to send a request (e.g., report) to the network for performing measurements of CSG cells in the vicinity of a neighbor or a given frequency or RAT. To allow the WTRU to request such measurement configuration, a new measurement report type (e.g., inter-frequency or inter-RAT) or event may be introduced. In one option, the WTRU may introduce two events. An example of an event or measurement type may be: for example, for the first case where the WTRU is first located in the vicinity of an inter-frequency HNB and therefore does not have stored HNB characteristics. Another exemplary event or type may be: for example, for the second case, where the WTRU knows that the allowed neighbor HNBs are located in one frequency or RAT due to the stored characteristic information.

For example, in the first case, where the WTRU has no capability to determine whether it is within the coverage of an allowed HNB, the WTRU may introduce a new event or report, described as "requesting a gap for detecting inter-frequency HNBs". For example, in UMTS, this event may be referred to as event 2 g. For LTE, this event may be referred to as event a 6. Although this event is referred to as event 2g or a6, it may take any other number, name, or type. Although the term "request.

This new event/report may be triggered as a result of initiating a manual HNB search, which may now be allowed in connected mode. Because the WTRU is in connected mode (e.g., CELL _ DCH), it cannot measure frequency without interrupting service. Thus, once the manual search is initiated, the WTRU may trigger event 2g to indicate to the network that it wishes to make measurements on the HNB frequency (if the network has previously configured the WTRU with a measurement order for such an event). The network may then configure the WTRU with gaps and accordingly, the WTRU may detect the HNB PSC (or PCI) on at least one frequency (if available). Although CELL _ DCH is shown as an exemplary state, the methods and apparatus described herein may also be applied to WTRUs in CELL _ FACH state.

The event 2g may be triggered in other ways than by a manual search trigger. For example, when the WTRU is equipped with GPS, event 2g may also be triggered by location type detection. For example, if the WTRU detects that it enters the urban area (or any particular preferred HNB area), it may send event 2g to the network. Otherwise, no event is triggered. For another example, event 2g may be triggered by periodic HNB searches defined in the WTRU (e.g., upon expiration of a timer). The duration of this timer may be fixed or configurable by the network or the user. According to this example, upon expiration of the timer, the WTRU is triggered for performing HNB search in the current frequency (and, optionally, in at least one frequency and system). An event for requesting a gap may also be triggered if the WTRU detects that the desired PSC or PCI (or optionally HNB) is in the neighbor list provided to the WTRU.

It is also possible for the WTRU to perform measurements on the HNB frequency without using any measurements or compressed mode gaps. This may occur at the following times: for example, when the WTRU is configured with Continuous Packet Connectivity (CPC) Discontinuous Reception (DRX) (for UMTS) in CELL _ DCH or DRX in LTE with little traffic activity. In this exemplary embodiment, event 2f or 2g may optionally be triggered only when the WTRU does not detect the PSC or PCI of the HNB after the timer expires (e.g., the timer may have started in response to a manual search request or detecting a matching signature). This timer may be stopped if/when the WTRU detects the PSC or PCI of the HNB (e.g., according to the DRX occasion). In another option, the timer may also stop after a predefined or previously signaled inter-frequency measurement time (performed during the DRX occasion) has expired.

Optionally, as part of a new measurement event, the WTRU may indicate the reason for its being triggered, such as a manual search, a periodic search by the WTRU, the location, and the PSC/PCI in the neighbor list. The neighbor list may be provided by the network and include the PSC/PCI of cells located adjacent to the WTRU. As described above, the whitelist may include the CSG ID of the HNB that the WTRU is allowed to access. The neighbor cell may or may not have its CSG ID as part of the WTRU whitelist.

In a second case, if the WTRU detects, by using the stored feature information, that at least one HNB with a CSG ID stored in its Universal Subscriber Identity Module (USIM) or white list is likely using the same frequency or different RAT as the serving macro cell and is close to its current location (in the vicinity of the macro cell), the WTRU may introduce, trigger and send a new event/report/message to the network indicating that a CSG is nearby (e.g., the WTRU is entering an area where a CAG cell is available and the CSG identity of the CSG cell is in the WTRU list). Upon receiving this report, the network may configure the WTRU to selectively use the gaps for measurements so that the WTRU may measure the PSC or PCI corresponding to the HNB on one or more applicable frequencies.

The new report may correspond to a new event in an existing measurement type (e.g., inter-frequency type, 2x or Ax group), and may be referred to as event 2h in UMTS and a7 in LTE, for example, and may be named "one or more HNBs on different frequencies match the current WTRU location". Alternatively, the same event/report may be used for both the first and second cases described above. The event may be merged in one event, for example (e.g., event 2g for UMTS and event a6 for LTE). The event may be triggered based on any of the above conditions, alone or in combination.

In another embodiment, the WTRU may use existing events to report the preference for measuring neighbor HNBs in one frequency even if the estimated quality of the currently used frequency is above a certain threshold. This can be achieved for UMTS, for example, by extending the existing events, such as event 2 f. Extending the event may be performed by: for example, by adding a one-bit Information Element (IE) (e.g., flag) indicating that the event is an HNB trigger and that the WTRU wishes to measure HNBs on a different frequency or system. For UMTS, additional IEs may be added in any IE, such as the measurement report structure, event results, inter-frequency event results, and extensions to sub-IEs containing event 2f information. For LTE, additional IEs may be added, for example, as a non-critical extension of the measurement report message or a non-critical extension of the measurement result IE.

In another embodiment, the WTRU may use the new measurement group type to notify the network of HNB related events described herein. These HNB events in the new measurement type may be referred to/configured as measurement type 8, for example, and may be referred to as CSG reporting type. For example, an 8x event may be defined for UMTS, while a Cx event may be defined for LTE. These new measurement types may be used for frequency or RAT measurements. For example, the WTRU may request a gap using a new event 8a ("request gap for detecting inter-frequency PSC"). Alternatively, the WTRU may introduce two new events, e.g., 8a and 8 b. A new event may be used in the first case: wherein the WTRU has no feature information and another new event may be used in a second scenario: where the WTRU has characteristic information (e.g., similar to 2g and 2 h). Two separate events may be defined for inter-frequency and inter-RAT PSC detection requests. Alternatively, one event or measurement type may be used for both frequency and RAT requests. This common measurement type is used by the WTRU to report to the network that it has detected that an allowed CSG is located in the vicinity of the current location.

Alternatively, a new Radio Resource Control (RRC) message may be defined by which the WTRU may report that the CSG is located nearby. This new message may carry the same information as the other embodiments described above.

Although the above embodiments are described in the context of inter-frequency measurements, the embodiments are equally applicable to requesting gaps to detect HNBs for both inter-RAT scenarios (e.g., if a WTRU is attempting to measure and handover from a UMTS macro cell to an LTE HeNB) and intra-frequency scenarios. It should also be understood that the triggering criteria may be similar to the inter-frequency case. In the inter-RAT case, a new inter-RAT event may be added (e.g., event 3e for UMTS and B3 for LTE, "request gap for detection of HNBs on another system"). Alternatively, a new event from the new HNB events may be defined (e.g. 8x for UMTS or Cx for LTE, "request a gap for detecting HNBs for other systems"). Alternatively, an existing 3x event may be reused as described herein.

The new event/report, which is part of the new measurement type, 8 may be the same as in the case of inter-frequency use. For example, an event 8a or a report may be used to "request gaps for detecting HNBs" or (using the same terminology as above), "one or several HNBs match the current WTRU location". In this case, once the event/report is triggered, it may also include an optional information element that indicates whether the WTRU wishes to perform measurements on inter-frequency, RAT, or both.

In general, the network may use WTRU-provided information to determine whether a measurement configuration, which may include gaps, should be allocated, and the duration of the gaps, if desired. The duration of the gap may depend, for example, on the number of frequencies that the WTRU must measure.

Optionally, a new IE may be added to the report to indicate the reason the event report was triggered. To give a non-limiting example, this may include one or a combination of the following: the manual search, the periodic search of the WTRU, the location, the characteristics matching at least one HNB stored in the WTRU white list, and the PSC being in a neighbor list. This may be combined in any of the embodiments described herein.

In another embodiment of triggering proximity indication reporting, LTE macrocell connections may have a higher priority than UMTS HNBs. Although described with respect to LTE macro cells and UMTS HNBs, the description herein may be applicable to other RAT combinations of macro cells and HNBs. In this embodiment, if the WTRU is connected to an LTE macro cell and it detects that it is close to a UMTS HNB, which is a member of the UMTS HNB, through the stored feature information, then the WTRU does not have to trigger an automatic search (i.e., it does not send an HNB proximity indication to the network). This automatic search may be initiated in the above described environment as long as the LTE macrocell channel conditions are deteriorating (i.e. the channel quality falls below a given threshold). The conditions for triggering the search and the measurement report indicating the proximity indication may occur if: 1) the current macro serving cell is LTE; 2) one of the WTRUs stores characteristics that match the UMTS HNB (i.e., the UMTS HNB is in the vicinity of the WTRU); and 3) the macro cell quality is below a certain threshold. This threshold may be configured by the network, may be a fixed value used by the WTRU or may be determined by the WTRU. It may be a general value or a value for each cell.

If these conditions are met, the WTRU may then send a measurement report to the network for requesting a measurement configuration, which may include gaps for detecting the PSC and obtaining a Master Information Block (MIB) (optionally with the scheduling block of the UMTS HNB and system information block 3(SIB 3)). If conditions 1 and 2 are satisfied and condition 3 is not, the WTRU may not send any report to the network to trigger HNB measurements.

Alternatively, if the PSC of a UMTS HNB is above a threshold, the WTRU may still automatically measure the channel quality of the PSC of a UMTS HNB that is in the vicinity of the WTRU and that triggered the search. Such an option may be for a configured time period. Such triggers may be used in combination with other triggers described herein.

Described now are examples of information contained in a report.

Optionally, as part of the report, additional information may be reported to the network (if available to the WTRU) by way of non-limiting example, including one or a combination of known frequencies of one or more HNBs that trigger a neighbor report and/or known RATs of one or more CSG cells that trigger a report (e.g., LTE or UMTS) stored on the WTRU's whitelist.

The WTRU may also optionally include information pertaining to the CSG or CSG(s) that triggered the report, such as the PSC of the known HNB/PSI of the CSG cell or CSG cells stored on the WTRU whitelist, and the WTRU CSG ID portion of the whitelist. The WTRU may also include the CGI in the report sent to the network. This additional information may help the WTRU detect "false" feature matches (e.g., the WTRU determines that the HNB included in the whitelist is in its vicinity, although this is not the case). In this example, if the eNB or RNC receives a CGI in the gap request report, it can verify that the HNB with the corresponding CGI is actually present. However, if the CGI is not identified, the eNB or RNC may decide not to configure the measurement configuration for the WTRU. Thus, if the WTRU does not receive a gap configuration (or other measurement configuration) from the network within a certain time period after requesting the network to configure it for measurements and/or gaps, the WTRU may decide to delete the corresponding feature from its memory to avoid unnecessary gap requests in the future. Alternatively, or in addition, the network (e.g., eNB or RNC) may explicitly indicate to the WTRU that the cell that owns the CGI corresponding to the CGI reported by the WTRU does not exist. Using this information, the WTRU may then delete the corresponding feature as in the previous example. The network may also use CSG ID information (if provided by the WTRU) for similar purposes.

Optionally, in the following deployment: the network, knowing all nearby CSG cell frequencies in the deployment and recognizing that no CSG cells corresponding to the CSG cell that the WTRU reports as part of its whitelist are available, may not allocate any gaps. Instead, the network may optionally send an RRC message (e.g., measurement control) back to the WTRU indicating that no such CSG cell is available and that the WTRU does not have to measure the inter-frequency HNB. The WTRU may then update its HNB features accordingly.

Optionally, together with the proximity indicator, the WTRU may signal that a given HNB in the vicinity of the WTRU has priority. This may help the network allow the WTRU to measure the HNB and potentially provide a measurement configuration that may include gaps.

In the following cases: for example, in the case where no handover occurs, the network may need to explicitly release the measurement configuration or gap allocated to allow the WTRU to detect HNB PSC/PCI on one frequency or RAT. Different reasons may trigger the interruption/release of the measurement configuration, which may already include gaps, for example: after a certain period of time, the WTRU has not detected HNB PSCs (and therefore has not reported to the network); the quality of HNBs detected in a frequency or other system is below a certain threshold; the WTRU detects only HNB PSCs that are not on its whitelist; the WTRU detects that it is leaving the vicinity of an allowed HNB (e.g., an HNB whose CSG is included in the WTRU's whitelist) by using stored HNB characteristics (e.g., there are no longer matching characteristics); the WTRU makes measurements but cannot find any HNBs with CSG IDs in the whitelist; and no acceptable HNBs were detected.

The network or WTRU may trigger the release of the gap. For example, if the network does not receive any HNB PSCs reported by the WTRU after a certain period of time, it may reconfigure the WTRU for deactivating the gap. Alternatively, if the network knows the location of the WTRU and realizes that no inter-frequency HNBs are near the WTRU, it may also release gaps in the WTRU. The WTRU may release the gap according to any of the following embodiments.

In one embodiment, the WTRU may inform the network that it no longer needs measurement configuration (e.g., inform the network that it is leaving an area where there may be allowed CSG cells). Upon receiving this notification, the network may reconfigure the WTRU to remove the measurement configuration and optionally the gaps for the WTRU. When referred to hereafter, releasing a gap refers to releasing the measurement configuration for a CSG cell or removing the configuration.

This notification/report may be sent via a new inter-frequency event. For example, for UMTS, it may be type 2i, "request release of allocated gaps for detection of inter-frequency HNBs".

Alternatively, the WTRU may use a new measurement type for CSG reporting, e.g., 8. A new event/reason for reporting this event may be defined. This may be referred to as event 8b (or C2) "request release of a gap for detecting inter-frequency HNBs" for example, for requiring the network to release a gap (e.g. 8x for UMTS or Cx for LTE as described in the previous paragraph). It will be appreciated that the name of the event/trigger cause is illustrative in nature and any name or descriptor may be used. For example, when the trigger corresponds to "the WTRU detects that it is leaving the vicinity of an allowed HNB (e.g., an HNB whose CSG is included in the WTRU whitelist)," the WTRU cause may then be referred to as "the WTRU is leaving the CSG area".

In another embodiment, the WTRU may automatically release the gap after it detects that it no longer needs to measure the inter-frequency HNB, without waiting for a reconfiguration message from the network. The WTRU may also inform the network that it has released the gap through a new event, such as event 2j through UMTS, "allocated gap for detecting inter-frequency HNBs" has been released ". Alternatively, the WTRU may use HNB event types, such as 8x for UMTS or Cx for LTE as described herein. The new event may be referred to as, for example, 8C (or C3) "for detecting that a gap in inter-frequency PSCs has been released".

In another embodiment, the WTRU may reuse the existing measurement report event type and add it to a new IE for informing the network that the previously allocated gaps for detecting HNBs on other frequencies must be released. Alternatively, this new IE may indicate to the network that the WTRU has automatically released its slot. For example, for UMTS, event 2f may be modified to have an optional IE with a new enumerated type for indicating one of: a request to release the allocated gaps for detecting inter-frequency HNBs, or a notification that the WTRU has released the allocated gaps for detecting inter-frequency HNBs.

The WTRU may add an IE to the measurement report describing why the gap is to be released. The IE may indicate: for example, the inter-frequency HNB search timer has been exhausted or the stored HNB characteristics do not match.

Alternatively, a new RRC message may be defined and used by the WTRU to request or inform the network that one of the triggering conditions described above has been met. For a trigger where the WTRU detects that it is leaving the vicinity of its allowed HNBs (e.g., HNBs whose CSG is included in the WTRU whitelist), a new RRC message is used to indicate that the network WTRU is leaving the area. This new message may carry the same information as the other embodiments described above. This RRC message may be a new message or the same RRC message used to indicate that initial measurements are requested (e.g., when the WTRU enters the vicinity of the CSG cell).

The embodiments described herein for releasing the previously allocated measurement configuration and any gaps for detecting inter-frequency HNBs may also be used for inter-RAT (IRAT) cases. For example, the WTRU may attempt handover from a UMTS macro cell to an LTE HeNB. In the IRAT case, a new IRAT event may be added. For example, event 3f for UMTS and event B4 for LTE, "gap for detecting HNBs for other systems requesting release of allocations" may be added, or a new event from new HNB event 8c "gap for measuring other systems requesting release of allocations" may be defined. Alternatively, a generic event may be used as 8x (e.g., 8b) to inform the network that the measurement configuration and any gaps may no longer be needed. The generic event may be used for both inter-frequency and inter-RAT measurement configuration and gap release when the WTRU leaves the HNB cell.

Optionally, the gap may also be released once handover to the HNB occurs.

Although CELL _ DCH is shown as an exemplary state, the methods and apparatus described herein may also be applicable to WTRUs in CELL _ FACH state. In other connected mode states, e.g. CELL _ FACH state, a message similar to CELL _ DCH as described can be used for informing the network.

It will be appreciated that although the CELL _ DCH message is shown above as an exemplary state, the methods are also applicable in other connected mode states, such as CELL _ FACH. The messages described herein for notifying the network for the CELL _ FACH state may be similar to those described above, or alternatively, in the CELL _ FACH state, the WTRU may notify the network using, for example, a CELL UPDATE message. A new cause or information element may be used by the WTRU to indicate the reason why the CELL UPDATE message is being sent (e.g., entering or leaving the vicinity of the HNB).

One or a combination of the following example methods may be implemented for preventing the WTRU from requesting gaps too frequently.

In one example approach, the WTRU may not be allowed to request a gap for detecting HNB PSC/PCI more than a certain number of times within a certain time period. The periodicity (e.g., number of times or time period) may be signaled by the network, may be part of the broadcast information, or may be stored in the WTRU. Alternatively, this periodicity may be different for each HNB. For example, the periodicity may be high for a user's home HNB or low for other HNBs. This periodicity may also depend on the mobility of the user.

In another example approach, the network may know that there is no HNB in the vicinity of the WTRU and indicate to the WTRU that it is not allowed to request gaps (or trigger proximity reports) to detect HNB PSC/PCI in an existing signal (e.g., a new IE added to measurement control).

In another example method, the network may indicate to the WTRU in an existing signal that only gap requests based on feature matching are allowed and periodic requests are prohibited.

In another example method, the characteristic information in the WTRU may be maintained to ensure that the characteristic information is valid when the WTRU uses it to request a gap (i.e., to ensure that there are allowed HNBs in the vicinity of the WTRU). This process may be implemented using one or a combination of the following methods.

In one example embodiment, a validity timer for each HNB feature may be started when the feature is stored in the WTRU. When this timer expires, the WTRU may delete the feature associated with the HNB.

In another example embodiment, a periodic timer may be used to periodically delete all HNB features stored in a WTRU.

In another example embodiment, the network may request the WTRU to delete one or a list of all HNB features the WTRU has stored by sending an RRC message to the WTRU.

In another example embodiment, the WTRU may delete the associated feature when handover to a particular HNB is rejected by the network.

Embodiments of HNB PSC detection by transmission are described herein. In one embodiment, inter-frequency PSC (or PCI) detection may be performed on the serving macrocell frequency through transmission of the common pilot channel (CPICH) of the HNB (or transmission of the primary and secondary synchronization signals (PSS and SSS) of LTE). In this embodiment, only the CPICH (for UMTS) or PSS/SSS (for LTE) is transmitted without any System Information Block (SIB). The signals required to detect PSC or PCI (CPICH for UMTS, PSS/SSS pair with LTE) are transmitted by the HNB on the serving macrocell frequency. Optionally, a Master Information Block (MIB) may be broadcast that specifies the HNB frequency and that cell is an HNB cell in addition to the CPICH. A WTRU performing intra-frequency measurements may detect the PSC and may thus request gaps from the network for performing additional measurements on the HNB's corresponding frequency (if known or otherwise indicated from signaling of the macro cell). The WTRU may have to rely on the characteristic information or even make measurements on all other frequencies if not known from the signaling and other indications of the macro cell.

The gap may be requested with one or a combination of the following conditions: the WTRU detects the PSC (or PCI) of the HNB; the WTRU detects HNB PSC (or PCI) in its whitelist; the WTRU detects HNB PSC (or PCI) contained in a known signature location; the WTRU performs a manual search and detects that there is an HNB in a neighbor frequency; the WTRU performs periodic searches; the WTRU detects HNB PSC (or PCI) in a reserved PSC or PCI range of a hybrid cell; and the WTRU detecting HNB PSC (or PCI) in the reserved PSC range or PCI range of the CSG cell.

The following describes signaling for support of HNB PSC/PCI detection methods with respect to inbound mobility support.

The different HNB PSC/PCI detection methods disclosed herein may be fully or only partially supported by a WTRU. The WTRU may indicate to the network the methods it supports by adding a new IE to an existing RRC message (e.g., in an RRC connection request or RRC connection setup complete) or in a new RRC message. The WTRU may indicate to the network one or a combination of the following capabilities: a) the WTRU can request a gap to detect HNB PSC/PCI on one frequency (e.g., inter-frequency or intra-frequency for the same RAT as the macro cell); b) the WTRU can request a gap for detecting HNB PSC/PCI in different RATs; and c) the WTRU is capable of detecting the PSC/PCI of the inter-frequency HNB that transmits the CPICH of UMTS or the PSS/SSS of LTE of the inter-frequency HNB on the serving macro cell frequency. As described above, the requested gap may correspond to the ability to detect the proximity or proximity of a CSG cell whose CSG belongs to the white list of the WTRU.

Additionally, through explicit signaling, the network may disable any of the above-mentioned supported methods in the WTRU.

Even if the WTRU supports the above mentioned capabilities, the network needs to support this mobility procedure. Typically, both the WTRU and the network need to support mobility in the case where the WTRU enters or leaves the vicinity or proximity of the HNB. As described herein, if the WTRU is aware that the network supports inbound mobility and the WTRU also supports inbound mobility, the WTRU may request or be able to detect and trigger a request for measurement configuration and any gaps or triggering events.

To determine that the network supports inbound mobility and more specifically the triggers described above, one or a combination of the following methods may be used. For illustrative purposes, inbound mobility may refer to the ability to detect a neighboring HNB and send/receive reports/events in response to proximity detection (e.g., when a WTRU enters/leaves the vicinity (proximity) of the HNB). In one example method, events that trigger a detection mechanism for inbound mobility are configured by the network through measurement control/configuration messages. If such measurement type or event is not configured (e.g., not in a configuration message), the WTRU determines that inbound mobility detection is not supported. Depending on the configured measurements, the WTRU implicitly determines whether inter-frequency, inter-RAT, or intra-frequency mobility is supported. For example, when a new measurement type 8 is introduced as described above, an inter-frequency or intra-frequency CSG detection mechanism may be configured for a certain RAT. If not, the WTRU then determines that the network does not support the inbound detection mechanism for the given RAT, thereby disabling functionality.

In another example method, the network explicitly signals to the WTRU that inbound mobility is supported to the HNB at the time of the RRC connection procedure. The network may notify the WTRU of the change in capabilities if the WTRU moves to an area that does not support inbound mobility.

In another example method, the network may explicitly indicate whether inter-frequency inbound mobility is supported, whether inter-RAT mobility is supported, or whether intra-frequency inbound mobility is supported. In the case of inter-RAT mobility, the network may also explicitly indicate whether only LTE to HNB UMTS mobility, UMTS to LTE HNB mobility, or any inter-RAT mobility is supported.

Events similar to those described above may also be used, where the WTRU may provide any of the above-described information to the network.

Figure 7 illustrates a method 700 for implementing the examples and embodiments described herein in the case where a WTRU enters an HNB cell or frequency. Upon entering a cell or frequency of the HNB, the WTRU and the network perform a capability exchange to determine whether the WTRU and the network support inbound mobility. The network may need to configure the WTRU with events that trigger measurements. The WTRU detects that it has entered the vicinity of an HNB cell whose CSG ID is in the WTRU's white list (705), for example, by means of the characteristic information. The WTRU then indicates to the network that it has entered the vicinity of an HNB whose CSG ID is in the WTRU's white list (715). The indication or request message may include HNB information, such as the frequency or RAT on which the HNB triggered the report. The indication or request message may be sent via a Radio Resource Control (RRC) message or a measurement report. The measurement report may include a proximity indication. The WTRU then receives a measurement configuration message, which may include gaps and PSC/PCI for measurements, from the network, base station, or other similar entity determined by the system architecture or structure (725), and performs the measurements to detect PSC or PCI (735). The WTRU may then send a measurement report to the base station (745). The measurement report may contain an Information Element (IE) including, for example, detection results, measurement results, of cells on frequencies added by measurement configuration and existing mobility events, e.g., event type 1D or 1A.

Fig. 8 illustrates a method 800 for implementing the examples and embodiments described herein in the case of a WTRU leaving an HNB cell or frequency. As with fig. 7, a capability exchange may be performed between the WTRU and the network, including sending configuration information for events that trigger measurements. Initially, the WTRU detects that it is leaving the vicinity of an HNB cell whose CSGID is in the WTRU's white list (805), through the use of, for example, profile information. The WTRU then indicates to the network, base station, or similar entity that may rely on the system that it is leaving the HNB area (e.g., it no longer needs to be allocated a measurement configuration or gap for obtaining the PSC or PCI of the HNB) (815). The indication or request message may be sent via a Radio Resource Control (RRC) message or a measurement report. The WTRU then receives a configuration message from the network, base station, or similar entity depending on the system to release a measurement configuration, which may already include a gap (825), and the WTRU then releases the configuration (835).

Described herein are additional embodiments. In one example embodiment, the WTRU may be configured for Discontinuous Reception (DRX) and may have sufficient idle time for detecting PSCs and reading system information of HNBs. If the macro cell quality is good, the WTRU may begin handover procedure evaluation. To limit the power usage of the WTRU, a limit may be applied to the duration during which the WTRU attempts to acquire the SIB. For example, the WTRU may stop the inter-RAT handover procedure when a timer expires.

In another embodiment, in the case where event B1 is configured by the network, where event B1 is "inter-RAT neighbor becomes better than threshold", the WTRU may not report or trigger the event when: the WTRU connects to a macro cell such as LTE, and the inter-RAT neighbor cell that becomes better than the threshold is, for example, a UMTS HNB. In this example, the LTE macro cell may have a higher priority than the umts hnb. If the WTRU detects that the PSC corresponds to an HNB, the WTRU may trigger a measurement report indicating event B1 and additionally send a proximity indication. The proximity indication may be added to the same measurement report or a different measurement report that may be used to start the automatic search in the WTRU. As indicated previously, the roles of the particular RATs may be interchanged in the examples and used here as an illustrative example.

This new restriction on inbound mobility from the macro LTE cell to the UMTS HNB may prevent a user with a WTRU that supports LTE but has a UMTS HNB from handing off to the UMTS HNB if the UMTS HNB is under the coverage of an LTE macro cell. One method of connecting to a UMTS HNB may be to drop the connection to the LTE macro cell so that the WTRU may camp on the UMTS HNB in idle mode. Alternatively, if the user wants to handover to a UMTS HNB while in connected mode, an optional indicator may be added to the stored feature information for the UMTS HNB that will force the WTRU to perform an inter-RAT handover or initiate an automatic search from an LTE macro cell to this particular UMTS HNB. For example, a flag in the feature information may be used as an absolute priority indicator for UMTS HNBs. In this example, regardless of the RAT or frequency the WTRU is connected to, the HNB has priority over all other macro cells, triggering an automatic search, and a proximity indicator is transmitted to the network. Additional information may be added to the proximity indication including the RAT and the priority associated with the RAT.

In another example approach, this inter-RAT automatic search or handover may also be initiated by the user using a manual search even though the previously described conditions for measuring HNBs in other RATs have not been met. In this example, if the WTRU detects that a search has been initiated and the WTRU has a stored HNB on another RAT in its profile, the WTRU may immediately attempt to decode the NB in its profile. Alternatively, even if the conditions discussed above are not met, the manual search by the user may trigger the WTRU to decide that a proximity indication in the measurement report may be sent to the network to initiate measurement and detection of the HNB. In this approach, the manual trigger by the user may override the priority set between the RAT and the HNB.

In another example approach, it may be noted that the WTRU may prefer the member HNB over the serving macro cell on a different RAT. Such preference handling may occur when the HNB uses the same RAT as a reference HNB, which may include, for example, an HNB installed in the user's home or any HNB indicated by the user. The reference HNB may be indicated by feature information stored in the WTRU. The rules restricting inter-RAT inbound handovers may include satisfying the following conditions: 1) the current macro serving cell is on a different RAT than the target HNB; 2) matching a target HNB using a different RAT than the reference HNB with the characteristic information stored in the WTRU; and 3) the macro cell quality is below a certain threshold. This threshold may be configured by the network, may be a fixed value used by the WTRU or may be determined by the WTRU. The threshold may be a general value or a value for each cell. Alternatively, the condition may need to last for a given period of time.

If all three conditions are met, the WTRU sends a measurement report to the network requesting a measurement configuration that may include gaps for detecting PSC/PCI, acquiring system information, or requiring authorization to use automatic gaps. If only condition 1 and condition 2 are met, the WTRU may not send any report to the network to trigger HNB measurements. Alternatively, the WTRU may still send a measurement report indicating that the proximity indication corresponds to an HNB, and may include the RAT of the HNB in the measurement report. Upon an explicit indication from the network, the network may choose to allow the WTRU to start searching and measuring for HNBs that belong to the RAT but not to the macro serving cell.

In another example approach, the priority between the RAT and the HNB may be set explicitly by the network. The network may explicitly indicate to the WTRU that the LTE macro cell and/or LTE HNB has higher priority than umts HNB. Such that the WTRU may initiate a UMTS HNB search (i.e., in its vicinity) if the quality of the LTE macro cell or LTE HNB is below the above-mentioned threshold. Other examples may include LTE HNBs with higher priority than UMTS macro cells, and vice versa.

The mobility priority indication between the macro cell on one RAT and the HNB in another RAT may be different from the inter-RAT priority of macro-to-macro cell mobility. For example, even if LTE has a higher priority inter-RAT macro-to-macro, the same rules may not be available when the UMTS HNB is in its vicinity. In this case, either UMTS HNB may be signaled that it has a higher priority or signaled that it has a higher priority through implicit rules. If the HNB in the other RAT is not signaled a priority indication, the WTRU may assume: 1) HNBs have priority as in the normal inbound mobility case; 2) HNBs in other RATs inherit the same inter-RAT mobility priority as indicated by the macro-to-macro rules; or 3) it will act according to one of the rules described above. The HNB priority settings described herein may also be applied in the same frequency for HNB to macro cell priority.

The inbound HNB priority indication (applicable to frequency or RAT) may be set for all CSGs belonging to a RAT or frequency, or may be set on a per CSG basis. Upon successful registration, the priorities of the CSG and RAT may be set and optionally updated thereafter. For example, for certain CSGs (e.g., the user's home CSG), the network may prefer that the WTRU attempt to connect to this CSG even if the WTRU is located/connected to other frequencies or RATs. However, for some CSGs, the network may prefer that the WTRU not connect to this CSG (i.e., connect only if the quality of the current macro cell is below a threshold).

Alternatively, an absolute HNB RAT priority and optionally an absolute frequency priority may be signaled. For example, the network may assign different RAT priorities. For example, if the detected HNB has a higher HNB RAT priority than the RAT or frequency to which the WTRU is connected, the WTRU may attempt to initiate an automatic search to connect to this HNB. If the detected HNB is in a lower priority HNB RAT, it may start an automatic search if the quality of the current RAT or frequency is below a certain threshold. The thresholds described in this disclosure for the currently connected RAT may be similar to the thresholds used for normal inter-RAT mobility, or alternatively HNB specific thresholds that are less stringent and may allow the WTRU to connect to the HNB earlier. The priority may be indicated by signaling or in the broadcast system information.

Typically, when a WTRU's nearby HNB has a higher priority than the current macro cell (based on any of the frequency and/or RAT priority settings described above), the WTRU may initiate an automatic search (e.g., attempt to perform a handover to this HNB). The automatic search may, for example, comprise a measurement report and/or a transmission of a proximity indication to the network and/or an attempt to read the SI. If this HNB has a lower priority than the current RAT, an automatic search may be triggered if the quality of the current macro cell is below a threshold, and optionally if the quality is below a threshold for a configured amount of time. This criterion is similar to the criterion described above for fixed priority setting.

In some cases, there may be a large number of opportunities for inter-RAT inbound handover attempts. For example, a user may purchase an HNB for one RAT and then upgrade to another HNB using a different RAT. In other cases, they may have a WTRU using one RAT and an HNB on another RAT, and then decide to purchase an HNB with the same technology as the WTRU. Additionally, some WTRUs may support multiple RATs, while other WTRUs may support separate RATs. These situations may result in many WTRUs making inter-RAT inbound handover attempts. This is undesirable because too much battery is used and service degrades. To limit the number of handover evaluation procedures when a user is in macro cell coverage and moving between HNBs of different RATs, the WTRU may use a special CSG inter-RAT trigger time, which is longer than a timer configured by the network. Alternatively, there may be a CSG inter-RAT offset added to the configured trigger time. In these cases, the event report is therefore not triggered too quickly when a feature match occurs. Because most HNBs are deployed for service enhancement purposes, it is acceptable for a WTRU to maintain connectivity on a macro cell for longer periods of time to limit unnecessary inter-RAT inbound handovers. For example, if the following condition is satisfied: 1) a WTRU is connected to a macro cell of a certain RAT; 2) the WTRU detects feature matching of HNBs for different RATs; and 3) during the inter-CSG RAT trigger time, the WTRU verifies that the HNB quality is above a certain inter-CSG RAT threshold, then the WTRU may report the measurement event for this HNB to the network.

The WTRU may also report a measurement event for this HNB to the network if conditions 1 and 2 are met but condition 3 is not met and the quality of the macro serving cell is not acceptable (e.g., below a certain threshold). Otherwise the WTRU does not send a measurement report and maintains the connection to the macro serving cell.

The CSG inter-RAT trigger time may be used by the WTRU when evaluating inter-RAT events B1, B2 for LTE and 3A, 3C events for UMTS or new events specified for HNBs. The CSG inter-RAT threshold may be configured by the network, but may also be a threshold determined by the WTRU so that the WTRU may give some preference to the member HNBs.

Alternatively, condition 3 may be deleted and condition 2 may also be replaced by optional condition 2 in case the WTRU may detect a feature match for HNB on a different RAT and verify the feature match during the CSG inter-RAT trigger time. In this option there may not be any condition on the HNB signal quality, but it is assumed that in case of feature matching the quality of the HNB should be good.

In another embodiment, the WTRU may be specified to have to maintain a connection to the macro serving cell for a certain period of time before its triggering event to start inter-RAT HNB handover measurements. The timer duration may be signaled by the network or may be a predetermined value known to the WTRU. It may also be a value stored in the profile for each HNB so that a WTRU may handover to a certain HNB faster than to other HNBs. If the timer has not expired, but the serving macro cell quality is no longer acceptable (e.g., below a certain threshold), the WTRU may be allowed to trigger an event to start handover measurements for the HNB on a condition that no other neighbor macro cells with good quality are available. For example, it may be decided that handover from a UMTS macro cell to an LTE HNB may occur faster than handover from an LTE macro cell to a UMTS HNB.

In order for the WTRU to establish a list of feature information for other RATs HNBs in idle mode, the WTRU needs to know the PCI/PSC split (split) of CSG cells for the other RATs. For example, while the LTE PCI split may be broadcast in the UMTS system information, the UMTS PSC split may be broadcast in the LTE system information. While the UMTS SIB11bis can be enhanced by using the new IE "LTECSG PCI decomposition info", the LTE SIB4 can be enhanced by using a new IEUMTS-CSG-PSC-RANGE. inter-RAT HNB partition information may also be added to other existing SIBs or to new SIBs. This allows the WTRU to identify which detected PSC/PCI belong to other RAT CSG cells, either in an automatic search or a manual search. In storing the feature information, the WTRU may also store the RAT type of the CSG cell (e.g., LTE or UMTS) so that once the WTRU is in connected mode, the WTRU may apply the rules defined for inter-RAT inbound mobility as described herein. Alternatively, the PSC/PCI split for other technologies may be signaled to the WTRU through dedicated RRC signaling (e.g., measurement control). The network may periodically provide PSC/PCI split for other RATs, or reporting may begin with one or a combination of the following triggering conditions, including: 1) macro cell measurements reported by the WTRU to the network to indicate that macro cell quality is deteriorating (e.g., below a certain threshold); 2) user activity is increasing, resulting in a demand for higher data rates; and 3) the network detects that the WTRU is in the vicinity where only HNBs of a different RAT from the macro serving cell are available or just a few HNBs of the same RAT as the current macro serving cell are available.

Examples

1. A method implemented in a wireless transmit/receive unit (WTRU) for detecting a home node-B or home (evolved) node-B (HNB) includes detecting that the WTRU has entered a vicinity of an HNB cell whose Closed Subscriber Group (CSG) ID is in a whitelist of the WTRU based on profile information.

2. The method of any preceding embodiment, further comprising sending an indication to a network entity that the WTRU has entered the vicinity of the HNB cell.

3. The method as in any one of the preceding embodiments, further comprising receiving a measurement configuration message.

4. The method of any preceding embodiment, further comprising performing the measurement.

5. The method of any preceding embodiment, wherein the indication is sent to the network entity by one of a new measurement type in a measurement report message or as a new Radio Resource Control (RRC) message.

6. The method of any preceding embodiment, wherein the measurement configuration message is used to detect one of a Primary Scrambling Code (PSC) or a Physical Cell Identity (PCI) of an HNB cell on a requested frequency and Radio Access Technology (RAT).

7. The method of any of the preceding embodiments, wherein the WTRU is configured to measure frequencies or Radio Access Technologies (RATs) in one of a compressed mode or a measurement gap.

8. The method of any preceding embodiment, wherein the measurement configuration message may be one of an intra-frequency measurement, an inter-frequency measurement, or an inter-RAT measurement.

9. The method of any preceding embodiment, wherein the indication comprises at least one of a frequency, a radio access technology, or a cell identity of an HNB cell that triggered the report.

10. The method of any preceding embodiment, further comprising signaling support for HNB cell detection on a frequency and RAT.

11. The method of any preceding embodiment, further comprising receiving a configuration for a RAT, wherein the configuration enables proximity detection and enables transmission/reception of reports in response to proximity detection on a condition that the WTRU enters or leaves the vicinity of the HNB cell.

12. The method according to any of the preceding embodiments, wherein the configuration is provided in the form of a new measurement type.

13. The method according to any of the preceding embodiments, wherein the configuration is provided in an RRC message.

14. The method of any preceding embodiment wherein the WTRU begins using the characteristic information to detect the vicinity of an HNB cell on the configured RAT.

15. The method of any preceding embodiment, further comprising detecting that the WTRU is leaving the vicinity of the HNB cell whose CSG ID is in the whitelist of the WTRU and notifying the network entity.

16. The method according to any of the preceding embodiments, further comprising receiving a configuration to remove the measurement configuration.

17. The method of any preceding embodiment, wherein the notification is transmitted via one of a measurement report message or a new RRC message.

18. The method according to any of the preceding embodiments, wherein the measurement report message and the new RRC message are further used for sending an indication to the network entity.

19. The method as in any one of the preceding embodiments, wherein the WTRU is not allowed to send the indication more than a certain number of times during a certain period of time.

20. A wireless transmit/receive unit (WTRU) for detecting a home node B or home (evolved) node B (hnb), the WTRU comprising a processor.

21. The WTRU of embodiment 20 further comprising a receiver in communication with the processor.

22. The WTRU as in any one of embodiments 20-21 further comprising the processor and receiver configured to detect that the WTRU has entered a vicinity of an HNB cell whose Closed Subscriber Group (CSG) ID is in a whitelist of the WTRU based on the characteristic information.

23. The WTRU as in any one of embodiments 20-22 further comprising a transmitter in communication with the processor.

24. The WTRU as in any one of embodiments 20-23 further comprising the transmitter configured to send an indication to a network entity that the WTRU has entered the vicinity of the HNB cell.

25. The WTRU as in any one of embodiments 20-24 further comprising the receiver configured to receive a measurement configuration message.

26. The WTRU as in any one of embodiments 20-25 further comprising the processor configured to perform the measurements.

27. The WTRU as in any one of embodiments 20-26 wherein the indication is sent to the network entity by one of a new measurement type in a measurement report message or as a new Radio Resource Control (RRC) message.

28. The WTRU as in any one of embodiments 20-27 wherein the receiver is configured to receive a configuration for a RAT, wherein the configuration enables proximity detection and enables transmission/reception of reports in response to proximity detection on a condition that the WTRU enters or leaves the vicinity of the HNB cell.

29. The WTRU as in any one of embodiments 20-28 further comprising the receiver and processor configured to detect that the WTRU is leaving the vicinity of the HNB cell whose CSG ID is in the white list of the WTRU and notify the network entity.

30. A method comprising transmitting a notification requesting a configuration that allows an interval to detect and measure a primary scrambling code (PCS) or a physical cell identity of a home node b (hnb) for at least one frequency.

31. The method of embodiment 30, further comprising transmitting a request to perform inter-frequency or inter-RAT measurements to detect a neighbor HNB.

32. The method as in any one of embodiments 30-31 further comprising transmitting a request for an event if a wireless transmit/receive unit (WTRU) does not have any feature information and does not have the capability to ascertain whether it is in coverage of an HNB.

33. A method as in any of embodiments 30-32 further comprising transmitting a request for a name "request for gap for detecting inter-frequency HNBs".

34. A method as in any of embodiments 30-33 wherein an event is initiated as a result of initiating a manual HNB search that is now in connected mode.

35. The method as in any one of embodiments 30-34 wherein the WTRU is configured with compressed mode.

36. A method as in any of embodiments 30-35 further comprising detecting HNB PSCs on other frequencies.

37. A method as in any of embodiments 30-36 further comprising performing a periodic search for HNBs.

38. A method as in any of embodiments 30-37 further comprising performing an HNB search in a current frequency and at least one other frequency if a timer expires.

39. A method as in any of embodiments 30-38 further comprising triggering an event for requesting a gap if a desired PSC is detected in a neighbor list.

40. The method as in any one of embodiments 30-39 wherein a WTRU is configured with Continuous Packet Connectivity (CPC) Discontinuous Reception (DRX).

41. The method as in any one of embodiments 30-40 wherein the event is triggered only if the WTRU does not detect the PSC of the HNB after the timer expires.

42. The method of any of embodiments 30-41 wherein the timer is stopped when a PSC or PCI is detected.

43. The method as in any one of embodiments 30-42 further comprising sending an indication of a reason for the measurement event being triggered.

44. A method as in any of embodiments 30-43 wherein a WTRU has feature information and detects that at least one of the HNBs stored in its Universal Subscriber Identity Module (USIM) is using a different frequency than the serving macro cell and is near its current location by using its stored features.

45. The method as in any one of embodiments 30-44 further comprising triggering an event named "match one or several HNBs on different frequencies with current WTRU location".

46. The method as in any one of embodiments 30-45, further comprising reporting a preference for measuring HNBs in a neighboring frequency.

47. The method as in any one of embodiments 30-46 further comprising transmitting an additional one-bit Information Element (IE) indicating that an event is triggered for an HNB and that the WTRU wishes to measure the HNB on a different frequency or on a different system in response to event 2 f.

48. The method as in any of embodiments 30-47 wherein an additional IE is added to at least one of the following IEs: an extension of the measurement report structure, event results, inter-frequency event results, or sub-IEs containing event 2f information.

49. A method as in any of embodiments 30-48 further comprising providing a measurement event set for use by a WTRU to notify a network of HNB-related events.

50. A method as in any of embodiments 30-49 further comprising requesting a gap from a network via a Radio Resource Control (RRC) message to detect HNBs on other frequencies.

51. A method as in any of embodiments 30-50 further comprising providing an IE in the report to indicate a reason for the event being triggered.

52. The method as in any one of embodiments 30-51 wherein the reason for the event being triggered comprises at least one of: manual search, periodic search by the WTRU, location, matching of characteristics with characteristics of at least one HNB stored in the WTRU white list, or PSC in a neighbor list.

53. The method as in any one of embodiments 30-52 wherein the report comprises additional information including at least one of: a known HNB frequency stored on a white list of the WTRU, a known HNB PSC stored on a white list of the WTRU, a WTRU CSG ID portion of a white list, or a system type.

54. The method as in any one of embodiments 30-53 further comprising determining whether a compressed mode gap should be allocated and a duration of the gap.

55. The method as in any one of embodiments 30-54 wherein an RRC message is signaled indicating that no Closed Subscriber Group (CSG) cells are available and that the WTRU is not measuring inter-frequency HNBs.

56. A method as in any of embodiments 30-55 wherein a gap allocated for detecting HNB PSCs is explicitly released.

57. The method of any of embodiments 30-56 wherein the gap is released as a result of one of: the WTRU does not detect any HNB PSCs and therefore does not report any HNB PSCs to the network after a certain period of time, the quality of HNBs detected in other frequencies or systems is below a certain threshold, the WTRU only detects HNB PSCs that are not on its whitelist, the WTRU detects that it is leaving the vicinity of its allowed HNBs by using its stored HNB characteristics, the WTRU has measured but has not found any home HNBs with CSG IDs in its whitelist, or no acceptable HNBs have been detected.

58. The method as in any one of embodiments 30-57 wherein releasing the gap is network triggered.

59. The method as in any embodiments 30-58 wherein the release gap is WTRU triggered.

60. A method as in any of embodiments 30-59 wherein a notification is transmitted via an inter-frequency event, the notification indicating to the network that a gap is not required.

61. The method as in any one of embodiments 30-60 further comprising receiving a signal indicating that the WTRU deactivates the compressed mode.

62. The method of any of embodiments 30-61, further comprising automatically releasing the gap.

63. A method as in any of embodiments 30-62 further comprising transmitting a measurement report event with an IE indicating to a network that a gap previously allocated for detecting HNBs on other frequencies must be released.

64. A method as in any of embodiments 30-63 wherein an IE indicates to a network that a WTRU has automatically released its slot.

65. A method as in any of embodiments 30-64 further comprising transmitting a signal comprising an IE indicating a request to release a gap allocated for detecting inter-frequency HNBs.

66. A method as in any of embodiments 30-65 further comprising transmitting a notification including an IE indicating that the WTRU has released a notification allocated for detecting inter-frequency HNBs.

67. The method as in any one of embodiments 30-66 wherein the method further comprises transmitting an IE that expresses a reason for the gap release.

68. The method as in any one of embodiments 30-67 further comprising transmitting an RRC message requesting the network to release the gap.

69. A method as in any of embodiments 30-68 further comprising releasing the gap if a handover to an HNB occurs.

70. The method as in any one of embodiments 30-69 further comprising transmitting a common pilot channel (CPICH) without any System Information Blocks (SIBs).

71. A method as in any of embodiments 30-70 further comprising transmitting a Master Information Block (MIB) that indicates a frequency of a HNB and that indicates a HNB cell when the cell is in question.

72. The method as in any one of embodiments 30-71, further comprising: the method includes detecting a PSC while performing intra-frequency measurements and requesting a gap for performing additional measurements on a corresponding frequency of a HNB.

73. The method as in any one of embodiments 30-72 wherein a gap is requested under one of the following conditions: the WTRU detects the HNB PSC, the WTRU detects the HNB PSC in its whitelist, the WTRU detects the HNB PSC contained in a known signature location, the WTRU performs a manual search and detects the presence of an HNB in a neighbor frequency, the WTRU performs a periodic search, the WTRU detects the HNB PSC within a reserved PSC range of a hybrid cell, or the WTRU detects the HNB PSC within a reserved PSC range of a CSG cell.

74. The method as in any one of embodiments 30-73 further comprising blocking an excessive number of gap requests and gap allocations.

75. The method as in any one of embodiments 30-74 wherein the WTRU has a predetermined number of request gaps during a certain time period to detect HNB PSC/PCI.

76. The method as in any one of embodiments 30-75 wherein the periodicity is signaled by a network.

77. The method as in any one of embodiments 30-76 wherein the periodicity is part of the broadcast information.

78. The method as in any one of embodiments 30-77 wherein the periodicity is stored in the WTRU.

79. The method as in any one of embodiments 30-78 wherein the periodicity is different for each HNB.

80. The method as in any one of embodiments 30-79 wherein periodicity depends on user mobility.

81. The method as in any one of embodiments 30-80, further comprising: receiving a reject request gap for detecting HNB PSC/PCI in response to the network knowing that there are no HNBs in the vicinity of the WTRU.

82. The method as in any one of embodiments 30-81, further comprising: an indication is received in the existing signal that gap requests based only on feature matching are allowed and periodic requests are prohibited.

83. The method as in any one of embodiments 30-82, further comprising verifying the characteristic information.

84. The method as in any one of embodiments 30-83 wherein a validity timer is started for each HNB feature when the feature is stored in the WTRU.

85. The method as in any one of embodiments 30-84 wherein upon expiration of the validity timer, the feature associated with the HNB is deleted.

86. A method as in any of embodiments 30-85 wherein a periodic timer is used to periodically delete all HNB features.

87. A method as in any of embodiments 30-86 wherein at least one HNB feature is deleted upon receiving an RRC message.

88. A method as in any of embodiments 30-87 wherein at least one HNB feature is deleted upon handover rejection.

89. A method as in any one of embodiments 30-88 further comprising signaling HNB PSC/PCI deletion capability.

90. The method as in any one of embodiments 30-89 wherein signaling is accomplished with an IE.

91. The method as in any one of embodiments 30-90 wherein the signaling is accomplished with an RRC connection request message.

92. The method as in any one of embodiments 30-91 wherein the signaling is accomplished with an RRC connection setup complete message.

93. The method as in any one of embodiments 30-92 wherein the signaling indicates that the WTRU is capable of requesting a gap for detecting HNB PSC PCI on a different frequency.

94. The method as in any one of embodiments 30-93 wherein the WTRU is capable of requesting a gap for detection of HNB PSC PCI on different RATs.

95. The method as in any one of embodiments 30-94 wherein the WTRU is capable of detecting the PSC/PCI of an inter-frequency HNB transmitting the CPICH of UMTS or the PSS/SSS of LTE on the serving macrocell frequency.

96. The method as in any one of embodiments 30-95, further comprising deactivating the capability through explicit signaling.

97. The method as in any one of embodiments 30-96 further comprising requesting a measurement gap or a triggering event on a condition that the network and the WTRU are aware that inbound mobility is supported.

98. A method as in any of embodiments 30-97 further comprising receiving a configuration message for an event to trigger a measurement for inbound mobility.

99. The method as in any one of embodiments 30-98 wherein inter-frequency, inter-RAT, or intra-frequency mobility is supported based on a configuration message.

100. A method as in any of embodiments 30-99 wherein a signal indicating support of inbound mobility for a home node B is received at the time of an RRC connection procedure.

101. A method as in any of embodiments 30-100 wherein a signal is received while moving to an area supporting inbound mobility for a home node B.

102. A method as in any of embodiments 30-101 wherein a signal is received indicating support for RAT-seen mobility, inbound-in mobility, or inter-RAT mobility.

103. A method as in any of embodiments 30-102 wherein a signal is received indicating support for LTE to HNB UMTS mobility, UMTS to LTE HNB mobility, or inter-RAT mobility.

104. The method as in any one of embodiments 30-103 wherein a measurement event may be configured for intra-frequency measurements for a home node B (HeNB).

105. A method for detecting a false Home Node B (HNB) feature match to prevent a wireless transmit/receive unit (WTRU) from further attempting access to a non-existing HNB, the method comprising: generating a request for a gap allocation to detect and measure at least one of a Primary Scrambling Code (PSC) or a Physical Cell Identity (PCI) of a target Home Node B (HNB) for at least one frequency, the request further comprising a Cell Global Identity (CGI) corresponding to the target HNB; and transmitting the request.

106. The method of embodiment 105 wherein the CGI corresponding to the target HNB is stored in a whitelist of accepted HNBs in memory.

107. The method as in any one of embodiments 105-106 further comprising setting a timer that expires a predetermined period of time after transmitting the request.

108. The method as in any one of embodiments 105-107 further comprising removing the CSG corresponding to the target HNB from the whitelist if a response to the request is not received within a predetermined period of time after transmitting the request.

109. The method as in any one of embodiments 105-108 further comprising receiving a notification that a target HNB corresponding to the CSG does not exist, and removing the CGI corresponding to the target HNB from the whitelist in response to receiving the notification.

110. A wireless transmit/receive unit (WTRU), comprising: a transmitting unit configured to generate and transmit a request for a gap allocation to a Node B (NB) such that the WTRU may detect and measure at least one of a Primary Scrambling Code (PSC) or a Physical Cell Identity (PCI) of a target Home Node B (HNB) for at least one frequency, the request further including a Cell Global Identity (CGI) corresponding to the target HNB.

111. The WTRU as in embodiment 110 further comprising a memory configured to store a whitelist of accepted HNBs including CGIs corresponding to a target HNB.

112. The WTRU as in any one of embodiments 110-111, further comprising: a timer; and a processing unit configured to set a timer, the timer terminating a predetermined period of time after transmitting the request.

113. The WTRU as in any one of embodiments 110-112 wherein the processor is further configured to remove the CSG corresponding to the target HNB from the whitelist on a condition that a response to the request is not received within a predetermined period of time after the request is transmitted.

114. The WTRU as in any one of embodiments 110-113 further comprising: a receiver configured to receive a notification that a target HNB corresponding to the CSG is absent, the processor further configured to remove the CGI corresponding to the target HNB from the whitelist in response to receiving the notification.

115. A method for detecting a false Home Node B (HNB) feature match to prevent a wireless transmit/receive unit (WTRU) from further attempting access to a non-existing HNB, the method comprising: receiving a request to allocate a gap to a WTRU, the request including a Cell Global Identity (CGI) corresponding to a target HNB of the WTRU; and determining whether a HNB corresponding to the CGI exists, and transmitting a notification to the WTRU that the target HNB does not exist on a condition that the HNB corresponding to the CGI does not exist.

116. The method of embodiment 115 further comprising determining whether to allocate a gap to the WTRU if a target HNB exists and allocating a gap to the WTRU if an HNB exists within range of the WTRU.

117. The method as in any one of embodiments 115-116 further comprising determining whether a target HNB is present in range of the WTRU and transmitting a notification denying the request for gap allocation for the WTRU on a condition that the target HNB is not present in range of the WTRU.

118. The method as in any one of embodiments 115-117 further comprising transmitting a Radio Resource Control (RRC) message indicating that a target HNB corresponding to the CGI is unavailable.

119. A Node B (NB), the NB comprising: a receiving unit configured to receive a request to allocate a gap to a WTRU, the request including a Cell Global Identity (CGI) corresponding to a target HNB of the WTRU; and a processing unit configured to determine whether an HNB corresponding to the CGI exists, and transmit a notification that a target HNB does not exist to the WTRU on a condition that an HNB corresponding to the CGI does not exist.

120. The NB as in embodiment 119 wherein the processing unit is further configured to determine whether to allocate a gap to the WTRU if the processing unit determines that a target HNB exists and to allocate a gap to the WTRU if an HNB exists within range of the WTRU.

121. The method as in any one of embodiments 119-120 wherein the processing unit is further configured to control the transmitting unit to generate and transmit a notification denying the request for gap allocation for the WTRU if a target HNB is present in the range of the WTRU and if a target HNB is not present in the range of the WTRU.

122. The method as in any one of embodiments 119-121 wherein the processing unit is further configured to transmit a Radio Resource Control (RRC) message indicating that a target HNB corresponding to the CGI is unavailable.

123. A method for use in wireless communications, the method comprising: a connection mode switch decision is performed.

124. The method of embodiment 123 wherein the handover is an inter-frequency handover.

125. The method as in any embodiments 123-124 wherein the inter-frequency handover comprises transmitting the communication session from the first base station using the first frequency to the second base station using the second frequency.

126. The method as in any one of embodiments 123-125 wherein the switching is performed.

127. The method as in any one of embodiments 123-126 wherein the intra-frequency handover comprises transmitting a communication session from a first base station using a first frequency to a second base station using the first frequency.

128. The method as in any one of embodiments 123-127 wherein the handover is an inter-Radio Access Technology (RAT) handover.

129. The method as in any one of embodiments 123-128 wherein the inter-RAT handover comprises transferring a communication session from a first base station using a first RAT to a second base station using a second RAT.

130. The method as in any one of embodiments 123-129 wherein the handover is an intra-Radio Access Technology (RAT) handover.

131. The method as in any embodiment 123-130 wherein the intra-RAT handover comprises transferring a communication session from a first base station using a first RAT to a second base station using the first RAT.

132. The method as in any one of embodiments 123-131 wherein the first base station is a macro cell and the second base station is a home node b (hnb).

133. The method as in any embodiments 123-132 wherein the first base station is an HNB and the second base station is a macro cell.

134. The method as in any one of embodiments 123-133 wherein the macro cell is a Universal Mobile Telecommunications System (UMTS) node B.

135. The method as in any one of embodiments 123-134 wherein a macro cell is an evolved Long Term Evolution (LTE) evolved universal terrestrial radio access network (E-UTRAN) node B (eNB).

136. The method as in any one of embodiments 123-135 wherein the HNB is a UMTS HNB.

137. The method as in any one of embodiments 123-136 wherein the HNB is an LTE home E-UTRAN node b (henb).

138. The method as in any one of embodiments 123-137 wherein the HNB is a femtocell (femtocell).

139. The method as in any one of embodiments 123-138 wherein the HNB is configured to operate in a Closed Subscriber Group (CSG) environment.

140. The method as in any embodiments 123-139, wherein performing the connection mode switch determination comprises performing measurements associated with the first base station.

141. The method as in any embodiments 123-140 wherein performing the connection mode switch decision comprises performing measurements associated with the second base station.

142. The method as in any embodiments 123-141, wherein performing the connection mode switch determination comprises performing a measurement.

143. The method as in any embodiments 123-142 wherein performing the measurement comprises reading system information of the base station.

144. The method as in any embodiments 123-143 wherein reading system information comprises reading Primary Scrambling Codes (PSCs).

145. The method as in any embodiments 123-144 wherein reading system information comprises reading a Physical Cell Identifier (PCI).

146. The method as in any embodiments 123-145 wherein performing a connection mode switch decision comprises performing a preliminary connection verification.

147. The method as in any embodiments 123-146 wherein performing preliminary connection verification comprises evaluating whether a base station is on a white list.

148. The method as in any embodiments 123-147 wherein performing the connection mode switch decision comprises reporting the base station to the network.

149. The method as in any embodiments 123-148 wherein performing the connection mode switch determination comprises receiving a PSC/PCI split.

150. The method as in any one of embodiments 123-149 wherein performing the connected mode switch decision is performed at a wireless transmit/receive unit (WTRU).

151. The method as in any embodiment 123-150 wherein the WTRU is a member of a CSG associated with an HNB.

152. The method as in any embodiments 123-151, wherein performing the connection mode switch decision comprises comparing a quality measure of a signal received from the macrocell to a threshold.

153. The method as in any one of embodiments 123-152, further comprising: detecting that the WTRU is within range of the HNB.

154. The method as in any one of embodiments 123-153 wherein the detecting comprises evaluating stored information.

155. The method as in any embodiments 123-154 wherein the stored information comprises characteristics associated with an HNB.

156. The method as in any embodiments 123-155 wherein the information comprises a location of an HNB.

157. The method as in any embodiments 123-156 wherein performing the connection mode switch decision comprises initiating an automatic search.

158. The method as in any one of embodiments 123-157 wherein initiating an automatic search comprises reporting an HNB proximity indication to a network.

159. The initiating is performed in response to a channel condition of the macro cell becoming worse according to any of embodiments 123 and 158.

160. The method as in any of embodiments 123-159 wherein the initiating is performed if a channel quality exceeds a threshold.

161. The method as in any embodiments 123-160 wherein performing the connected mode switch decision comprises transmitting a measurement report to the network.

162. The method as in any embodiments 123-161 wherein the threshold is configured by a network.

163. The method as in any one of embodiments 123-162 wherein the threshold is a fixed value.

164. The method as in any embodiments 123-163 wherein the threshold is determined by the WTRU.

165. The method as in any embodiments 123-164 wherein the threshold is associated with a base station.

166. The method as in any one of embodiments 123-165 wherein the measurement report comprises a request for a scheduled measurement gap.

167. The method as in any one of embodiments 123-166 wherein the measurement report indicates proximity of an HNB.

168. The method as in any one of embodiments 123-167 wherein performing a connection mode handover decision comprises searching for and measuring an HNB in response to a message received from a network.

169. The method as in any embodiments 123-168 wherein the measuring comprises evaluating channel quality of a received signal comprising a PSC of an HNB.

170. The method as in any embodiments 123-169 wherein performing a connected mode handover decision comprises initiating a search if a channel quality of a received signal comprising PSCs is above a threshold.

171. The method as in any embodiments 123-170 wherein the measuring comprises performing a single measurement.

172. The method as in any embodiments 123-171 wherein the measuring comprises performing the measurement over a period.

173. The method as in any embodiments 123-172 wherein the WTRU is configured for Discontinuous Reception (DRX).

174. The method as in any embodiments of embodiments 123-173, further comprising: the connection mode switching decision is performed in response to expiration of the timer.

175. The method as in any one of embodiments 123-174 wherein the measurement report indicates initiation of an automatic search.

176. The method as in any embodiments 123-175 wherein the measurement report comprises a proximity indication.

177. The method as in any embodiments 123-176, wherein performing the connection mode switch determination comprises evaluating a priority.

178. The method as in any embodiments 123-177 wherein the priority is frequency dependent.

179. The method as in any embodiments 123-178 wherein the priority is related to a RAT.

180. The method as in any embodiments 123-179 wherein the priority is associated with a CSG.

181. The method as in any embodiments 123-180 wherein the priority is associated with an HNB.

182. The method as in any one of embodiments 123-181 wherein the information comprises a priority.

183. The method as in any embodiments 123-182 wherein performing the connected mode handover decision comprises evaluating a HNB based on a reference HNB.

184. The method as in any one of embodiments 123-183 wherein the initiating is performed during a predetermined period.

185. The method as in any embodiments 123-184 wherein the predetermined period is based on a network configured timer and offset.

186. The method as in any one of embodiments 123-185 wherein the initiating is performed with feature matching verified during a predetermined period.

187. The method as in any embodiments 123-186 wherein the initiating is performed on a condition that the WTRU has connected to the macro cell for a predetermined period.

Although the features and elements of the present invention are described in the particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements. The methods or flow charts provided herein may be implemented in a computer program, software, or firmware tangibly embodied in a computer-readable storage medium for execution by a general purpose computer or a processor. Examples of the computer-readable storage medium include Read Only Memory (ROM), Random Access Memory (RAM), registers, buffer memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and Digital Versatile Disks (DVDs).

For example, suitable processors include: a general-purpose processor, a special-purpose processor, a conventional processor, a Digital Signal Processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) circuit, any Integrated Circuit (IC), and/or a state machine.

A processor in association with software may be used to implement a radio frequency transceiver for use in a Wireless Transmit Receive Unit (WTRU), User Equipment (UE), terminal, base station, Radio Network Controller (RNC), or any host computer. The WTRU may be used in conjunction with modules, implemented in hardware and/or software, such as a camera, a video camera module, a video phone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, and BluetoothA module, a Frequency Modulation (FM) radio unit, a Liquid Crystal Display (LCD) display unit, an Organic Light Emitting Diode (OLED) display unit, a digital music player, a media player, a video game player module, an internet browser, and/or any Wireless Local Area Network (WLAN) or Ultra Wideband (UWB) module.

Claims (15)

1. A method implemented in a wireless transmit/receive unit (WTRU) for detecting a home node B or a home evolved node B (hnb), the method comprising:

the WTRU detecting that the WTRU has entered a vicinity of an HNB cell whose Closed Subscriber Group (CSG) ID is in a whitelist of the WTRU based on an autonomous search function;

the WTRU sending an indication to a network entity that the WTRU has entered a vicinity of the HNB cell, wherein the indication includes a frequency of the HNB cell and a Radio Access Technology (RAT) of the HNB cell;

the WTRU receiving a measurement configuration message; and

the WTRU performs a measurement in response to the measurement configuration message.

2. The method of claim 1, wherein the indication is sent to the network entity by one of: the new measurement type in the measurement report message is either as a new Radio Resource Control (RRC) message.

3. The method of claim 1, wherein the measurement configuration message is used to detect one of a Primary Scrambling Code (PSC) or a Physical Cell Identity (PCI) of the HNB cell over the frequency and the RAT.

4. The method of claim 3 wherein the WTRU is configured to measure the frequency or the RAT in one of a compressed mode or a measurement gap.

5. The method of claim 1, wherein the measurement configuration message is one of an intra-frequency measurement, an inter-frequency measurement, or an inter-RAT measurement.

6. The method of claim 1, wherein the indication comprises a cell identity of an HNB cell that triggered the indication.

7. The method of claim 1, further comprising signaling support for HNB cell detection on the frequency and the RAT.

8. The method of claim 1, further comprising receiving a configuration for the RAT, wherein the configuration initiates proximity detection and initiates sending/receiving of reports in response to proximity detection on a condition that the WTRU enters or leaves the vicinity of the HNB cell.

9. The method of claim 8, wherein the configuration is provided in one of a new measurement type or an RRC message.

10. The method of claim 8, wherein the WTRU starts using the autonomous search function to detect the vicinity of the HNB cell on the configured RAT.

11. The method of claim 1, further comprising detecting that the WTRU is leaving the vicinity of the HNB cell whose CSG ID is in the whitelist of the WTRU and notifying the network entity.

12. The method of claim 11, further comprising receiving a configuration for removing a measurement configuration.

13. The method of claim 12, wherein a notification is transmitted via one of a measurement report message or a new RRC message, and wherein one of the measurement report message and the new RRC message is also used to send the indication to the network entity.

14. The method of claim 1, wherein the WTRU is not allowed to send the indication more than a certain number of times during a certain period of time.

15. A wireless transmit/receive unit (WTRU) for detecting a home node B or a home evolved node B (hnb), the WTRU comprising:

a processor;

a receiver in communication with the processor;

the processor and the receiver configured to detect that the WTRU has entered a vicinity of an HNB cell whose Closed Subscriber Group (CSG) ID is in a whitelist of the WTRU based on an autonomous search function;

a transmitter in communication with the processor;

the transmitter is configured to send an indication to a network entity that the WTRU has entered a vicinity of the HNB cell, wherein the indication includes a frequency of the HNB cell and a Radio Access Technology (RAT) of the HNB cell;

the receiver is configured to receive a measurement configuration message; and

the processor is configured to perform measurements in response to the measurement configuration message.