HK1189117B - Access terminal assisted node identifier confusion resolution - Google Patents

Description

Access terminal assisted node identifier confusion resolution

The application is a divisional application of the Chinese invention patent application with the invention name of 'access terminal auxiliary node identifier confusion elimination' and the application number of 200980123015.4 (PCT/US 2009/048054).

Claiming priority based on 35U.S.C. § 119

The present application claims the benefit and priority of the following co-owned applications: U.S. provisional patent application No.61/074114, assigned attorney docket No. 081869P1, filed on 19/6/2008; U.S. provisional patent application No.61/087592, assigned attorney docket No. 082374P1, filed 8/2008; and U.S. provisional patent application No.61/156805, assigned attorney docket No. 091556P1, filed on 3, 2, 2009; the disclosure of each application is incorporated herein by reference.

Cross reference to related applications

This application is related to U.S. patent application No. _______, filed concurrently herewith and having in common the designation "access terminal assisted node identifier confusion removal using time gaps" (access terminal assisted device discovery information communication resource confusion gap) and having a designated proxy scheme number of 082374U1, the disclosure of which is hereby incorporated by reference.

Technical Field

The present application relates generally to communications and more particularly, but not exclusively, to eliminating confusion associated with a communication node.

Background

Wireless communication systems are widely deployed to provide various types of communication (e.g., voice, data, multimedia services, etc.) to multiple users. With the rapidly increasing demand for high-rate multimedia data services, there is a challenge to implement efficient and robust communication systems with enhanced performance.

To supplement conventional mobile telephone network base stations, small coverage base stations (e.g., installed in a user's home) may be deployed to provide more robust indoor wireless coverage for mobile units. Such small-coverage base stations are generally referred to as access point base stations, home nodebs, home enodebs, picocells, or femtocell base stations. Typically, such small-coverage base stations are connected to the internet and the mobile operator's network via a DSL router or a cable modem.

In practice, a larger number of small-coverage base stations (e.g., femtocells) may be deployed in a given area (e.g., within the coverage area of a given macrocell). Thus, two or more base stations that are close to each other may be assigned the same identifier, since the number of available identifiers is typically limited (e.g., the physical layer identifier may only be 10 bits long). Thus, when a node (e.g., an access terminal) in the network reports to its serving base station (e.g., a handover source) that a signal is being received from a base station having a given identifier, there may be confusion as to which base station (e.g., a handover target) is referred to. Moreover, due to such confusion, the handover source may not know whether the access terminal has access rights at the target because the handover source does not know the full identity of the handover target. Accordingly, there is a need for effective techniques to identify a base station so that other nodes in the network can efficiently communicate with the base station.

Disclosure of Invention

The following is a summary of example aspects of the disclosure. It should be understood that any reference herein to the term "aspect" may refer to one or more aspects of the disclosure.

The present disclosure relates in some aspects to eliminating confusion associated with node identifiers. For example, a limited number of node identifiers may be defined within the network such that more than one node (e.g., access point) in the network is assigned the same identifier. Thus, confusion regarding the identity of a target node (e.g., a target access point) may occur when handing off an access terminal from a serving node (e.g., a source access point) to the target node. Various techniques for eliminating such confusion are described herein.

In some aspects, an access terminal to be handed off to a target node may assist in eliminating confusion related to the target node by obtaining a unique identifier associated with the target node. Here, a unique identifier may be defined, for example, as a globally unique identifier, an identifier that is unique within a network, or an identifier that is more unique than another node identifier (e.g., an identifier that has more bits than other node identifiers, but need not be completely unique within a network or globally, etc.). To facilitate the access terminal acquiring the unique identifier, the network may provide a time gap during which the access terminal may temporarily stop monitoring transmissions from the source node so that the access terminal may receive transmissions from potential target nodes. In some cases, the access terminal sends a unique identifier to the serving node, which the serving node may then use to initiate a handover operation. In some cases, the access terminal initiates a handoff operation using the unique identifier.

In some aspects, the disclosure relates to a serving node that sends an indication of an asynchronous time gap (e.g., a measurement gap or a discontinuous transmission indication) to access terminals served by the serving node. The asynchronous time gap may not begin and end at defined times. For example, an asynchronous time gap can begin upon receipt by an access terminal of a message indicating a time gap. Moreover, the asynchronous time gap can end upon the access terminal just receiving the unique identifier from the target node. Thus, the asynchronous time gap may also have no defined duration.

In some embodiments, a signal threshold may be assigned to a group identifier that has been identified as likely to be assigned to a node affected by confusion. This threshold may then be used to trigger the access terminal to acquire the unique identifier and/or to trigger a confusion determination operation at the serving node. For example, if the access terminal detects a signal from an access point assigned one of these identifiers, and if the detected signal exceeds a threshold, the access terminal may automatically acquire a unique identifier of the access point or the access terminal may report the receipt of the signal to its serving access point. In the latter case, the serving access point may then determine whether the access terminal should attempt to acquire the unique identifier.

In some aspects, the disclosure is directed to an access terminal that initiates a handover operation at a target node after determining whether to allow the access terminal to access the target node. For example, after obtaining the unique identifier of the target node, the access terminal may determine whether it is allowed to access the target node (e.g., using the permission list). If access is allowed, the access terminal may initiate a forward handover at the target node.

In some aspects, the present disclosure relates to a serving node that prepares multiple target nodes for potential handover if there is node identifier confusion. For example, upon receiving an indication that the access terminal has detected a signal from a target node assigned a given identifier, the serving node may determine whether there is or may be confusion. To this end, the serving node identifies a plurality of potential target nodes that are assigned this same identifier. The serving node may then prepare some or all of these potential target nodes for potential handoffs of the access terminal.

In some embodiments, a serving node may send information to an access terminal relating to the preparation of a potential target node. The access terminal may then determine whether the target node that the access terminal hears is one of the prepared target nodes. If so, the access terminal completes the handover to the target node using the corresponding handover preparation information it received from the source node.

Drawings

These and other exemplary aspects of the disclosure will be described in the detailed description and appended claims that follow, wherein:

FIG. 1 is a simplified block diagram of various exemplary aspects of a communication system for eliminating confusion;

fig. 2 is a simplified diagram illustrating a coverage area for wireless communications;

FIG. 3 is a simplified block diagram of exemplary aspects of components that may be used in a communication node;

FIGS. 4A and 4B are flow diagrams of various exemplary aspects of operations that may be used to enable an access terminal to acquire a second type identifier;

FIGS. 5A, 5B, and 5C are flow diagrams of various exemplary aspects of operations that may be used to enable an access terminal to acquire a second type identifier;

6A, 6B, 6C, and 6D are flow diagrams of various exemplary aspects of operations that may be performed in connection with an access terminal initiating connection reestablishment at a target;

7A, 7B, 7C, and 7D are flow diagrams of exemplary aspects of operations that may be performed in connection with preparing multiple targets for handover;

8A, 8B, 8C, and 8D are flow diagrams of various exemplary aspects of operations that may be performed in connection with providing handover preparation information to an access terminal;

FIG. 9 is a simplified diagram of a wireless communication system;

fig. 10 is a simplified diagram of a wireless communication system including a femto node;

FIG. 11 is a simplified block diagram of exemplary aspects of a communications component; and

fig. 12-16 are simplified block diagrams of various exemplary aspects of an apparatus for eliminating identifier confusion as taught herein.

In accordance with common practice, the various features shown in the drawings are not necessarily drawn to scale. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may be simplified for clarity. Accordingly, the drawings may not depict all of the components of a given apparatus (e.g., device) or method. Finally, the same reference numerals may be used throughout the specification and drawings to refer to the same features.

Detailed Description

Aspects of the disclosure are described below. It should be apparent that the teachings herein may be embodied in a wide variety of forms and that any specific structure, function, or steps disclosed herein are merely representative. In light of the teachings herein, those skilled in the art will recognize that an aspect disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. Further, such an apparatus may be implemented or such a method may be practiced using other structure, functionality, or structure and functionality in addition to or other than one or more of the aspects set forth herein. Furthermore, an aspect may include at least one element of a claim.

Fig. 1 illustrates a plurality of nodes in an example communication system 100 (e.g., a portion of a communication network). For purposes of illustration, various aspects of the disclosure will be described in the context of one or more access terminals, access points, and network nodes in communication with each other. However, it should be recognized that the teachings herein may be applied to other types of devices described using other terminology or other similar devices. For example, in various embodiments, an access point may be referred to or implemented as a base station or eNodeB, an access terminal may be referred to or implemented as a user equipment or mobile device, and so on.

The access points in system 100 provide one or more services (e.g., network connectivity) to one or more wireless terminals (e.g., access terminal 102) that may be installed or may roam within the relevant geographic area. For example, at various points in time, an access terminal 102 may connect to access point 104, any one of a set of access points 1-N (represented by access points 106 and 108 and associated ellipses), or access point 110. Each of the access points 104 and 110 may communicate with one or more network nodes (represented for convenience by network node 112) to facilitate wide area network connectivity. Such a network node may take various forms, such as one or more radio and/or core network entities (e.g., a configuration manager, a mobility management entity, or some other appropriate network entity).

Each access point in system 100 may be assigned a first type of identifier, referred to herein as a node identifier. In various embodiments, such an identifier may include, for example, a physical cell identifier ("PCID"), a pseudo-random number ("PN") offset, or an acquisition pilot. Typically, a fixed number (e.g., 504) of node identifiers are defined in a given system. In this case, identifier confusion often occurs when a large number of access points are in the same vicinity, as multiple access points may end up using the same identifier.

Fig. 1 shows a simple example in which both access point 106 and access point 110 are assigned "identifier 1". As the access terminal 102 roams within the system 100, the access terminal 102 may handoff from a source access point (i.e., a serving access point to which the access terminal is currently connected, such as access point 104) to a target access point (e.g., access point 110). The decision to handoff the access terminal 102 to the target access point may be based on whether the access terminal 102 is receiving a particularly strong signal (e.g., a pilot signal) from the target.

In the example of fig. 1, the access terminal 102 (e.g., identifier controller 114) identifies signals from potential target access points by node identifiers associated with (e.g., embedded in) the signals. Upon receiving a signal from a potential target, the access terminal 102 may send a message (e.g., a measurement report) including the identifier to its current serving access point. If a decision is made to perform a handover, the serving access point (i.e., the source access point of the handover) may communicate with the destination access point to reserve resources for the access terminal. For example, the environment information maintained by the serving access point may be communicated to the target access point and/or the environment information maintained by the target access point may be transmitted to the access terminal 102. Without confusion, a node identifier ("identifier 1") associated with the target access point may be mapped to a unique identifier associated with the target access point, thereby establishing communication with the target access point using the unique identifier. However, when there is confusion as in the example of fig. 1, the source access point may not be able to determine which access point is the desired target access point (e.g., access point 104 may not be able to determine whether to communicate with access point 106 or access point 110 to reserve resources for the access terminal).

In accordance with an aspect of the present disclosure, to eliminate such confusion, the access terminal 102 (e.g., the identifier controller 114) can be configured to obtain a second type identifier associated with the potential target. In some aspects, the second type of identifier may comprise a unique identifier broadcast by the potential target. For example, the second type identifier may be unique in a larger area than the first type identifier. In some embodiments, the second type identifier may be unique throughout the operator's network. In some embodiments, the second type identifier may be only more unique than other node identifiers (e.g., PCIDs). For example, the second type identifier may have more bits (e.g., 16 bits versus 10 bits) than other node identifiers. In this way, the likelihood of identifier confusion (e.g., from 10 targets to 2 targets) may be reduced. Thus, in this case, the second type identifier may not necessarily be completely unique among networks, global, etc. In various embodiments, such unique identifiers may include, for example, a global cellular identifier ("GCI"), an access node identifier ("ANID"), a sector identifier, an internet protocol address, or some other identifier that uniquely identifies an access point 110 within a network. By using such an identifier, a desired target access point for a handover operation may be uniquely identified.

The access terminal 102 may begin monitoring for the second identifier automatically or in response to a message from the serving access point. For example, in some cases, the access terminal 102 may begin acquiring the second identifier based on the signal strength of the first identifier. In some cases, upon receiving a measurement report with an obfuscated identifier from the access terminal 102, the access point 104 may instruct the access terminal 102 to acquire the second identifier.

In some cases, upon receiving a measurement report with an obfuscated identifier, the access point 104 (e.g., the time gap controller 116) may send a message including a time gap indication. During this time gap, the access terminal 102 may temporarily stop monitoring transmissions from the access point 104, thereby enabling the access terminal 102 to acquire the second identifier of the target access point. As described in more detail below, in some aspects, this time gap may comprise an asynchronous time gap without a synchronous start time (e.g., synchronous with a system clock).

According to one aspect of the disclosure, an access terminal may initiate connection reestablishment at a target access point if the access terminal determines that it may access the target access point. In some cases, accessibility may be determined by comparing an identifier obtained from a target access point to a list identifying access points to which access is permitted by the access terminal. For example, the access terminal 102 may maintain a list of closed user groups (corresponding to a set of one or more member access points) that the access terminal is allowed to access. Thus, upon acquiring a closed subscriber group identifier ("CSGID") of a potential target access point, the access terminal 102 (e.g., the handover controller 118) may use the allowed CSG list to determine whether to allow the access terminal 102 to access the target access point. If so, the access terminal 102 may make random access at the potential target to initiate connection re-establishment. Thus, in accordance with this aspect of the disclosure, an access terminal may initiate a connection re-establishment based on whether the access terminal is allowed access, as opposed to a conventional re-establishment initiated due to a radio link failure.

According to one aspect of the disclosure, an access point may prepare multiple potential targets for handover in the presence of confusion. For example, upon receiving a measurement report with a obfuscated identifier, the access point 104 (e.g., the handover controller 120) may identify a set of possible target candidates (e.g., a set of access points using the same identifier). The access points 104 may then prepare each of these access points for handover of the access terminal 102.

According to one aspect of the disclosure, an access point may send handover preparation information for the target of the group preparation to an access terminal to be handed over. For example, upon receiving handover preparation information from the access point 104 (e.g., the handover controller 120), the access terminal 102 (e.g., the handover controller 118) may determine whether a target access point identified by the second identifier acquired by the access terminal 102 has been prepared for handover by the access point 104. If so, the access terminal 102 may perform random access at the potential target to complete the handover.

Identifier confusion may generally occur in a network as follows: some access points provide macro coverage while other access points provide smaller coverage. For example, in the network 200 shown in fig. 2, the macro coverage area 204 (e.g., areas 204A and 204B) may be provided by macro access points of a large area cellular network, such as a 3G network, which is commonly referred to as a macro cellular network or wide area network ("WAN"). Further, the smaller coverage areas 206 (e.g., areas 206A and 206B) may be provided by access points of, for example, a residence-based or building-based network environment, which is commonly referred to as a local area network ("LAN"). As an access terminal moves through such a network, in some locations the access terminal may be served by an access point that provides macro coverage, while in other locations the access terminal may be served by an access point that provides smaller area coverage. In some aspects, smaller area coverage access points may be used to provide capacity growth, in-building coverage, and different services, all of which result in a more robust user experience.

In the description herein, a node that provides coverage over a larger area (e.g., an access point) may be referred to as a macro node, while a node that provides coverage over a smaller area (e.g., a residence) may be referred to as a femto node. It should be appreciated that the teachings herein may be applicable to nodes associated with other types of coverage areas. For example, a pico node may provide coverage over an area that is smaller than a macro area but larger than a femto area (e.g., coverage within a commercial building). In various applications, other terminology may be used to refer to macro nodes, femto nodes, or other access point type nodes. For example, a macro node may be configured or referred to as an access node, base station, access point, eNodeB, macro cell, and so on. Also, a femto node may be configured or referred to as a home nodeb, home eNodeB, access point base station, femtocell, and the like. In some embodiments, a node may be associated with (e.g., divided into) one or more cells or sectors. The cells or sectors associated with a macro, femto, or pico node may be referred to as a macro, femto, or pico cell, respectively.

In the example of fig. 2, a plurality of tracking areas 202 (or routing areas or location areas) are defined, each tracking area including a plurality of large coverage areas 204. Here, the coverage areas associated with tracking areas 202A, 202B, and 202C are depicted by thick lines, with macro coverage areas 204 represented by larger hexagons. As described above, the tracking area 202 may also include a femto coverage area 206. In this example, each femto coverage area 206 (e.g., femto coverage area 206C) is depicted within one or more macro coverage areas 204 (e.g., macro coverage area 204B). It should be appreciated, however, that some or all of the femto coverage areas 206 may not be within the macro coverage area 204. Also, one or more pico coverage areas (not shown) may be defined within a given tracking area 202 or macro coverage area 204.

In deployments where a large number of access points, such as femto and pico nodes, are located within a given area (e.g., dense urban deployments), two or more of these access points may be assigned the same node identifier. For example, in the macro coverage area 204A, the femto coverage areas 206A and 206D may be assigned the same identifier. In this case, node identifier confusion (e.g., PCID confusion) may occur because multiple neighboring nodes near the serving access point of the access terminal advertise the same node identifier. For example, in fig. 1, access points 106 and 110 may include femto nodes or pico nodes that advertise "identifier 1" via respective broadcast pilot signals. In addition, these access points may be in the vicinity of the access point 104 (e.g., macro access point) currently serving the access terminal 102. In this case, access point 104 may be aware of access points 106 and 110, and thus confusion may occur when instructing a handoff to the access point identified by "identifier 1".

In general, the confusion resolution techniques described herein may be applied to any kind of node. However, in many deployments, macro access points in a given area will be planned so that there is no confusion associated with handing over to the macro access points. In this case, the confusion resolution techniques taught herein may be applied to any non-macro node in the network. Such non-macro nodes may include, for example: nodes deployed in an unplanned manner. As described above, such non-macro nodes may include femto nodes (e.g., deployed by individuals) as well as operator-deployed low-power pico nodes. Also, as will be discussed in more detail below, the nodes may be restricted in some manner (e.g., restricting access). Thus, the confusion resolution techniques taught herein may be applied to restricted nodes (e.g., nodes associated with a closed user group).

In view of the above summary, various techniques that may eliminate confusion in accordance with the teachings herein will be described with reference to fig. 3-8C. Briefly, fig. 3 illustrates various components that may be used in an access point or an access terminal, and the flow diagrams of fig. 4A-8C are directed to various techniques for eliminating confusion.

For purposes of illustration, the operations of fig. 4A-8C (or any other operations discussed or taught herein) may be described as being performed by specific components (e.g., components of system 100 and/or components shown in fig. 3). However, it should be appreciated that these operations may be performed by other types of components and may be performed with a different number of components. It should also be appreciated that one or more of the operations described herein may not be employed in a given implementation.

Fig. 3 illustrates various exemplary components that may be incorporated into nodes, such as access terminal 102 and access point 104, to perform confusion resolution operations as taught herein. The components may also be incorporated in other nodes in the communication system. For example, other nodes in the system may include components similar to those described for the access terminal 102 and the access point 104 to provide similar functionality. A given node may contain one or more of the components. For example, an access terminal may contain multiple transceiver components that enable the access terminal to operate on multiple frequencies and/or communicate via different technologies.

As shown in fig. 3, the access terminal 102 and the access point 104 may include transceivers 302 and 304, respectively, for communicating with other nodes. The transceiver 302 includes a transmitter 306 for transmitting signals (e.g., messages) and a receiver 308 for receiving signals (e.g., including performing pilot signal searches). Similarly, the transceiver 304 includes a transmitter 310 for transmitting signals and a receiver 312 for receiving signals.

The access terminal 102 and access point 104 also include other components that may be used in conjunction with confusion resolution operations as taught herein. For example, the access terminal 102 and the access point 104 may include communication controllers 314 and 316, respectively, for managing communications (e.g., sending and receiving messages/indications) with other nodes and for providing other related functionality as taught herein. Further, the access terminal 102 and the access point 104 may include handover controllers 318 and 320, respectively (e.g., corresponding to the handover controllers 118 and 120 of fig. 1), for performing handover-related operations and for providing other related functionality as taught herein. The access terminal 102 and the access point 104 may include identifier controllers 322 (e.g., corresponding to the identifier controllers 114) and 324, respectively, for managing (e.g., selecting, obtaining, requesting, etc.) node identifiers and for providing other related functionality as taught herein. The access terminal 102 may include an access controller 326 for determining whether the access terminal 102 is allowed to access the node and for providing other related functionality as taught herein. The access point 104 may include a time gap controller 328 (e.g., corresponding to the time gap controller 116) for providing time gap indications (e.g., indications of time gaps sent in messages) for the access terminal 102 and for providing other related functionality as taught herein. The access point 104 may include an obfuscation controller 330 for performing obfuscation-related operations and for providing other related functions as taught herein. For example, the confusion controller 330 may automatically detect actual or potential confusion, or upon receiving an indication of confusion from the access terminal 102, the confusion controller 320 may further determine whether confusion exists or may simply attempt to resolve the confusion. In either of these cases, upon detection of confusion, the confusion controller 320 can perform or initiate various operations to eliminate confusion (e.g., request the access terminal 102 to obtain a unique identifier, provide a time gap, identify and prepare a target, etc.). Other example operations of the components of FIG. 3 are described below.

For convenience, the access terminal 102 and the access point 104 are shown in fig. 3 as including components that may be used in various examples described below in connection with fig. 4A-8C. In practice, one or more of the illustrated components may not be used in a given example. For example, in some embodiments, the access terminal 102 may not include the handover controller 318, and in some embodiments, the access point 104 may not include the time gap controller 328.

Fig. 4A and 4B depict a scenario in which an access terminal uses a network-configured time gap to obtain a second identifier (e.g., a unique identifier such as GCI) of a potential target. Such a scheme will be described for the case of an confusion resolution procedure in which the access terminal automatically determines whether to acquire the second identifier. For example, the access terminal may compare the signal strength of a signal associated with a first identifier of a node to a threshold to determine whether to acquire a second identifier. Thus, the access terminal may obtain the second identifier without being requested by another node (e.g., a serving access point).

As shown at block 402, at some point in time, a network (e.g., network node 120, such as an MME or serving access point) may configure a time gap for an access terminal. For example, in some cases, the network may configure a synchronous measurement gap that defines a specific start time of the measurement gap, a duration of the measurement gap, and a period of the measurement gap. The network may then send an indication of the defined measurement gap to the access terminal. In some cases, the time gap may be provided by indicating that discontinuous reception ("DRX") is to be employed.

Referring now to block 404, in some embodiments, a set of identifiers in a node identifier space (e.g., a PCID space) may be reserved for non-macro nodes to simplify confusion resolution. By using such a defined set of identifiers, a node receiving a signal comprising identifiers from the set can easily determine that identifier confusion is likely to occur. For example, it may be assumed or determined that certain femto nodes may be confused. Accordingly, the femto nodes can be assigned identifiers in the set such that any node that receives an identifier broadcast by one of the femto nodes can readily determine that a second identifier should be acquired to ensure confusion does not occur. In some embodiments, the set includes a set of specified values associated with access points specified as non-confusion exempt. In some implementations, the set includes a set of specified values associated with a closed user group (e.g., described below). In some embodiments, the set includes a set of specified values associated with access points of at least one specified type (e.g., node type). Such specified types may relate to, for example: one or more of transmit power, coverage area, or relay capacity.

Accordingly, at block 404, the access terminal may receive a defined set of identifiers of the first type. This list may include, for example, the set of node identifiers described above. In some implementations, this list can be received from a serving access point (e.g., the identifier controller 324 of the access point 104). For example, the serving access point may identify all PCIDs that are or may be obfuscated and provide a list of these identifiers to the access terminal. In some implementations, the set can be received from a configuration manager (e.g., network node 112) that tracks a reserved set of nodes assigned identifiers in the set. In some embodiments, the group may be generated based on information received from nodes in the system. For example, the target access point or some other access point may advertise an indication (e.g., via neighbor list information) that a second type identifier (e.g., GCI) must be used when accessing the target access point.

The access terminal may receive a threshold associated with the defined set of identifiers, as shown at block 406. For example, such a threshold may specify a threshold signal strength value that triggers the access terminal to acquire a received signal of the second type identifier. This threshold may be defined and/or provided by the serving access point or some other node. In some embodiments, this threshold may be defined as being below a received signal strength threshold (e.g., a few dB lower) that triggers a handover operation. In some embodiments, the threshold may be specified as a relative offset from the signal strength of the target access point or as an absolute threshold for the carrier-to-interference ratio ("C/I") from the target access point. In some cases, such a threshold may be defined to be equal to the signal strength of the signal from the current serving access point plus an offset.

At some point in time, the access terminal will receive a signal associated with (e.g., including) the first type identifier, as shown at block 408. This signal may be acquired, for example, when an access terminal connected to a macro access point initiates a search for a neighboring femto node (e.g., a home eNodeB). When the access terminal detects a signal from the femto node, the access terminal can obtain a first type identifier (e.g., PCID, PN offset, pilot ID, sector ID, etc.) from the signal.

The access terminal may then determine whether the received identifier is in the list of identifiers obtained at block 404, as shown at block 410. Further, the access terminal may determine whether the received signal strength of the signal received at block 410 is greater than or equal to the threshold obtained at block 406.

As shown at blocks 412 and 414, the access terminal may continue to monitor for signals from neighboring access points if the criteria of block 410 are not met.

As shown at block 416 of fig. 4B, if the criteria of block 410 are met, the access terminal (e.g., identifier controller 322) obtains a second type identifier (e.g., GCI) associated with the identifier received at block 408. Here, acquiring the second identifier may include monitoring for other signals from the target access point containing the second identifier. For example, the target access point may broadcast system information including the second identifier at a time interval that is less frequent than the time interval at which the target access point broadcasts the first identifier (e.g., PCID).

In some aspects, the access terminal utilizes a time gap configured by the network to acquire the second identifier (e.g., by monitoring for a signal from the target access point during the next available time gap). For example, in some embodiments, GCI is transmitted via a system information block (e.g., SIB 1) every 20 ms. Further, in some embodiments, each measurement gap is shorter than 20ms (e.g., 6 ms). Thus, in some cases, the first measurement gap instance may not overlap with the SIB 1. By making the length of the measurement period not a multiple of 20ms, subsequent measurement gaps can be aligned with targeted SIB transmissions. Therefore, it is desirable for the network to appropriately configure the periodicity of the measurement gap (e.g., 86 ms) to enable the access terminal to efficiently acquire the second identifier.

As shown at block 418, the access terminal (e.g., identifier controller 322) sends a message to the source access point including the identifiers obtained at blocks 408 and 416 and the received signal strength of the associated signal (e.g., the signal received at block 416). This message may be sent just after the second identifier is acquired at block 416, or at other times. In some embodiments, this information is sent in a measurement report. This report may be sent, for example, once the received signal strength of the received signal (e.g., pilot from the target access point) exceeds a handoff threshold.

As shown at block 420, when any potential confusion associated with the first identifier obtained at block 408 is eliminated by obtaining the second identifier, the access point (e.g., the handover controller 320) determines whether to initiate a handover operation based on the second identifier and the received signal strength provided in the message. If a handover operation is indicated, the access point will use the second identifier to prepare the target access point (e.g., by sending a handover preparation message). In addition, the access point sends a handover command (e.g., an RRC reconfiguration message) to the access terminal. The access terminal may then communicate with the target and complete the handover (RRC reconfiguration complete).

In some aspects, the schemes of fig. 4A and 4B may exhibit advantages in high mobility environments. For example, such a scheme may enable faster handover since the GCI may be read before the signal strength of the target access point is strong enough for the required handover. Moreover, the number of measurement reports generated by access terminals in the system can be reduced as compared to other techniques, as measurement reports can be issued only after a corresponding reporting threshold (e.g., RRC reporting threshold) is exceeded.

As noted above, some of the operations described herein may not be employed in every embodiment. For example, in some implementations, the set of identifiers (e.g., the range of obfuscated PCIDs) may not be provided to the access terminal at block 404. In this case, the access terminal may report all identifiers of the first type that it hears. In some cases, making such reports may still be subject to threshold constraints (e.g., reporting only those signals that exceed a threshold).

Fig. 5A through 5C depict a scheme in which an access terminal uses asynchronous time gaps to obtain a second identifier (e.g., a unique identifier such as GCI) of a potential target. Such a scheme will be described for the case where the access terminal reports to the access point a confusion resolution procedure that received a signal that exceeds a threshold (e.g., a GCI resolution threshold). The access point then determines whether confusion occurs or is likely to occur and, if so, instructs the access terminal to acquire a second identifier (e.g., GCI). Here, the operations of blocks 502-512 may be similar to the operations of blocks 404-414 of fig. 4, respectively. Therefore, these operations will not be described again.

At block 514 of fig. 5A, if the received identifier is in the list and the received signal strength exceeds the threshold (at block 510), the access terminal sends a message to the access point including the identifier and the received signal strength of the associated signal obtained at block 506. This message may be sent just after the identifier is obtained at block 506, or at other times. In some embodiments, this information is sent in a measurement report.

As shown at block 516 of fig. 5B, the access point (e.g., identifier controller 324) receives a message from the access terminal. The access point (e.g., the confusion controller 330) then determines whether multiple nodes are likely to use the same identifier (i.e., determines whether the received identifier can be used to identify at least one node other than the target access point). This can be judged, for example, by: by comparing the identifiers to a list that indicates which identifiers have been or may be assigned to different access points in the network (e.g., the list is maintained at the access point or elsewhere); by determining whether the identifier belongs to a defined set of identifiers (e.g., a set of obfuscated identifiers provided at block 502); or otherwise determined. Thus, by determining whether there is confusion associated with using the received identifier (e.g., whether confusion occurs or is likely to occur), the access point can provide identifier confusion detection based on the received information. Here, the confusion detection may be based on whether multiple nodes are actually using the same identifier or whether it is likely (e.g., highly likely) that multiple nodes will use the same identifier. Further, the determination may optionally be based on the received signal strength of any detected signals associated with the identifier.

If no confusion is detected, the access point may proceed with standard operation, as shown in blocks 518 and 520. For example, the access point may determine whether handover is warranted and, if so, determine a second identifier for the target based on the first type identifier received via the measurement report.

Conversely, as shown at block 522, if confusion is detected, the access point will send one or more messages to the access terminal. For example, the access point may send a request to request the access terminal to obtain a second identifier (e.g., CGI) associated with the received identifier. Further, the access point (e.g., time gap controller 328) can send an asynchronous time gap indication to the access terminal to enable the access terminal to temporarily stop monitoring transmissions by the access point. This will allow the access terminal to more effectively monitor transmissions from the target access point during the time gap to acquire the second identifier.

As described above, asynchronous time slots do not have synchronous timing. For example, in contrast to conventional measurement gaps, asynchronous time gaps have no defined period (e.g., begin at some periodically occurring frame number). Thus, the asynchronous time gap may not have a determined start time (e.g., a start time that is synchronized to the system clock). As a specific example, in some cases, an asynchronous time gap may be defined to begin when an access terminal receives an indication of a time gap. Further, the asynchronous time gap may not have a determined end time (e.g., a specified time that is synchronized to the system clock). For example, in some cases, an asynchronous time gap may be defined to end when the access terminal acquires the second identifier. Thus, with asynchronous time gaps, the access terminal can automatically exit the network configured time gap. Thus, the asynchronous time gap may not have a determined duration. However, in some cases, a maximum limit (e.g., 4-5 seconds) may be defined, after which monitoring of the second identifier is terminated.

The time gap may be defined in various ways. In some embodiments, the time gap may be implemented as a measurement gap. In some embodiments, the time gap may be implemented with discontinuous reception.

The access point may send an indication of the time gap to the access terminal in various manners. In some cases, the access point may send the indication along with the request for the second identifier (e.g., in the same MAC frame as the request). In some cases, the access point sends an RRC reconfiguration message with a measurement gap or DRX configuration.

The access terminal (e.g., identifier controller 322) receives the request including the indication, as shown at block 524. In addition, the access terminal (e.g., communication controller 314 that determines when to transmit and receive) receives the time gap indication. Advantageously, in this case, the next time slot for reading the second identifier may be available immediately upon reception of the message. Accordingly, the access terminal (e.g., receiver 308) may immediately monitor for transmissions from the target access point to obtain the second identifier as described below, as indicated at block 526. The time gap may then be terminated (e.g., once the second identifier is obtained) as shown in block 528 of fig. 5C. As shown at block 530, the access terminal (e.g., identifier controller 322) responds to the request of block 522 by sending a message (e.g., a measurement report) to the access point that includes the second identifier.

As shown at block 532, the access point receives the message, thereby enabling the access point to resolve the confusion. Here, the access point receive message may serve as an indication to the access point that the time gap has ended.

As shown at block 534, the access point (e.g., the handover controller 320) may determine whether to initiate a handover based on the second identifier and the received signal strength (e.g., as described herein). If a handover is indicated, the access point will use the second identifier to prepare the target access point (e.g., by sending a handover preparation message). The access point sends a handover command to the access terminal, which communicates with the target to complete the handover.

One or more of the operations described above may not be employed in a given implementation. For example, in some implementations, the set of identifiers (e.g., the range of obfuscated PCIDs) may not be provided to the access terminal at block 502. In this case, the access terminal may report all identifiers of the first type that it hears. In some cases, making such reports may still be subject to threshold constraints.

In some embodiments, the threshold test may also be omitted. For example, the access terminal may instead simply report each identifier of the first type that it hears. Upon receiving these reports, the access point may determine for each identifier whether confusion exists or may exist (e.g., at block 516). If confusion is detected herein, the access point may send a request for a second identifier to the access terminal along with the time gap indication (e.g., at block 522). The access terminal may then return a report of the second identifier and, if granted, may begin the handoff operation as described above.

Fig. 6A-6D illustrate a scenario in which an access terminal initiates a connection re-establishment at a target if the access terminal determines that it is allowed to access the target. This scheme will be described with respect to the following confusion resolution procedure: wherein the access terminal reports the first identifier to the access point if the association signal exceeds the threshold and acquires the second identifier (e.g., GCI) upon receiving an indication of an asynchronous time gap from the access point. It should be appreciated, however, that the disclosure of fig. 6A-6D may be applied to other confusion resolution processes that do not include all of the operations described below. For example, asynchronous time gaps may not be used in some embodiments.

At some point in time, the access terminal will receive a signal (e.g., a pilot) from a potential target and acquire a first identifier (e.g., a PCID) associated with the potential target, as shown at block 602. Accordingly, the operations of block 602 may be similar to the operations of block 408 described above.

As shown at block 604, in some embodiments, an access terminal (e.g., access controller 326) may determine whether it may be in the vicinity of a potential target access point (e.g., the access point's cell) to which the access terminal may be allowed access. The access terminal may use various techniques to determine whether it is likely to be near such a potential target (e.g., a home eNodeB). For example, in some cases, the determination may be based on an automatic search. In some cases, the access terminal may use global positioning system techniques to determine its geographic location and associate that location with a known location of the potential target or other nodes in the vicinity of the potential target. In some cases, an access terminal may determine whether it is in the vicinity of a given access point based on signals received from other nodes in the vicinity of the potential target (e.g., based on phase delays of the received signals).

Based on the above determinations, an access terminal (e.g., access controller 326) can generate a corresponding indication (e.g., a likelihood indication referred to as a grant). For example, the indication may represent a probability of whether the access terminal is near a potential target.

As shown at block 606, the access terminal (e.g., identifier controller 322) determines whether the signal received at block 602 was reported received. The determination may be based on one or more criteria.

In some cases, the determination of block 606 is based on whether the signal strength of the received signal is greater than or equal to a threshold. For example, as depicted at block 406, such a threshold may be defined as equal to the signal strength of the signal from the current serving access point plus an offset.

In some cases, the determination of block 606 is based on a permission likelihood indication. For example, the access terminal may allow reception of the report signal if the indication meets or exceeds a defined probability.

As shown at blocks 608 and 610, the access terminal may continue to monitor for signals from neighboring access points if the criteria of block 606 are not met.

As shown at block 612, if the criteria of block 606 are met, the access terminal (e.g., identifier controller 322) sends a report message (e.g., measurement report) to its serving access point. This report message may include the identifier obtained at block 602 and the received signal strength of the associated signal. In some embodiments, the report message further includes a permission likelihood indication.

As shown at block 614 of fig. 6B, the access point (e.g., identifier controller 324) receives a message from the access terminal. The access point then determines whether to initiate a handover-related operation or to remain serving the access terminal. In some aspects, the determination may be based on a determination of whether multiple nodes are likely to use the reported identifier (e.g., a determination made by the confusion controller 330). Such operation may be performed, for example, as described at block 516.

In some cases, the determination of block 614 is based on a permission likelihood indication received from the access terminal. For example, if the indication indicates a low probability (e.g., below a threshold), the access point may not initiate a handover. Conversely, if the indication indicates a high probability (e.g., reaching a threshold or above), the access point may initiate a handover (e.g., conditioned on other handover criteria being met).

If it is determined that a handoff is not to be performed, the access point may continue normal operation (e.g., continue to serve the access terminal), as indicated at blocks 616 and 618.

As shown at block 620, if a decision is made to perform a handover and confusion is detected, the access point sends one or more messages to the access terminal. For example, an asynchronous time gap indication, as described above at block 522, can be transmitted to enable the access terminal to acquire the second identifier. Further, in some embodiments, the access point may send an indication of whether the access terminal is allowed to initiate connection re-establishment.

As shown at block 622 of fig. 6C, the access terminal (e.g., communication controller 314) receives the time gap indication and, in some cases, the reestablishment indication. As described above, the time gap for reading the second identifier may be started upon receiving the time gap indication.

As shown at block 624, the access terminal may monitor for transmissions from the target access point during the time gap. Accordingly, the access terminal (e.g., the indication controller 324) may obtain the second identifier as described at block 526. Further, in some embodiments, the access terminal (e.g., identifier controller 322) may obtain another identifier associated with the target access point. For example, the access terminal may obtain an indication of a group (e.g., a closed user group) to which the target broadcast by the target belongs. The time gap may then be terminated (e.g., once the identifier is obtained) as shown in block 626.

Referring now to block 628, as described above, in some embodiments, the access terminal may be conditionally allowed to initiate connection re-establishment. For example, an access terminal may be allowed to initiate connection re-establishment only if it receives authorization (e.g., by receiving a corresponding indication from a serving access point or some other node).

Accordingly, as shown at blocks 628 and 630, the access terminal (e.g., handover controller 318) determines whether it is allowed to initiate a connection re-establishment (e.g., based on whether an indication is received at block 620). If not, the access terminal may simply send a message (e.g., a measurement report) including the second identifier to the access point, as shown at block 632. The access terminal may then wait for the access point to determine whether to permit the handoff. If the access terminal is allowed to initiate connection reestablishment, the operational flow proceeds instead to block 634 of fig. 6D.

The access terminal (e.g., access controller 326) determines whether it is allowed access to the target access point, as shown at block 634. For example, as discussed in detail below, some access points (e.g., home enodebs) may provide access only to a selected group of access terminals (e.g., access terminals belonging to a certain user).

The determination at block 634 may be accomplished in a variety of ways. In some cases, an access terminal maintains a list of access points that the access terminal is allowed to access (which may be referred to as a permission list).

In some embodiments, the permission list may include a list of access points (e.g., identified by a unique identifier such as GCI) to which the access terminal is permitted access. In this case, upon obtaining the second identifier that uniquely identifies the potential target, the access terminal 102 may use the list to determine whether to allow the access terminal 102 to access the potential target.

In some embodiments, the permission list may include a list of one or more groups (e.g., identified by a group identifier such as a CSGID) to which the access terminal is allowed access. In this case, the access terminal 102 may compare the corresponding identifier (e.g., CSGID) it received from the target access point to the identifiers in the permission list to determine whether access is allowed.

If access is not allowed, the access terminal may continue to monitor for signals from neighboring access points, as shown in blocks 636 and 638.

If access is allowed, the access terminal (e.g., the handover controller 318) attempts to reestablish the current connection at the target access point, as shown at block 640. To this end, the access terminal may perform random access at the target access point and send a reestablishment request to the target.

The target access point may then initiate a forward handover by initiating backhaul signaling with the source access point to complete the handover, as shown at block 642. The target access point and the access terminal then exchange messages to complete the reestablishment and release the source access point to complete the handover (block 644). In this case, the initiation of the forward handover may serve as an indication to the access point to indicate that the time gap has ended.

Fig. 7A-7D depict a scenario in which an access point prepares multiple target nodes for handover if confusion is detected. In some aspects, this approach may reduce the time it takes to handoff the access terminal to the desired target. The schemes of fig. 7A-7D are also described with respect to the following confusion resolution process: if the association signal exceeds the threshold, the access terminal reports the first identifier to the access point, then acquires a second identifier (e.g., GCI) upon receiving an indication of an asynchronous time gap from the access point, and then initiates connection reestablishment at the target broadcasting the second identifier. Also, it should be appreciated that the disclosure of FIGS. 7A-7D may be applied to other confusion resolution processes that do not include all of the operations described below.

The operations of blocks 702-720 may be similar to the operations of blocks 602-620 of fig. 6, respectively. Therefore, these operations will not be described again.

As shown at block 722 of fig. 7B, in conjunction with providing a time gap to enable the access terminal to obtain the second identifier (block 720), the access point (e.g., the handover controller 320) may identify one or more target access points in preparation for handover. That is, in the event that identifier (e.g., PCID) confusion is detected, multiple potential targets may be prepared for handover to increase the likelihood of preparing a desired target to handle a reestablishment request from an access terminal. In this manner, handover may be completed more quickly upon receipt of a reestablishment message, as compared to the process of FIGS. 6A-6D, in which the source and target exchange handover command related messages after the reestablishment request is issued.

The access point may employ various schemes to identify potential targets in preparation for handoff. In some cases, the access point may prepare all access points that it knows will use the same identifier as the reported identifier. In some cases, the access points may choose to prepare only a portion of the access points. Following are several examples of criteria that may be used to select an access point to prepare for handover.

In some embodiments, access points known to allow the access terminal are prioritized for handover preparation. For example, from the CSGID of the access point appearing in the access terminal's allowed CSG list, it can be known that the access terminal is allowed at the access point. The access terminal may be known to be allowed at an access point that is either an unrestricted CSG access point or a hybrid CSG access point. The access terminal may be known to be allowed at an access point that is an open access point from the access point. In contrast, access points known not to allow access terminals may not be prepared for handover. Accordingly, the access terminal (e.g., the handover controller 320) may receive an indication of whether the access terminal is allowed to access an access point and distinguish the identified priority of block 722 based on the indication.

In some embodiments, access points in the vicinity of the current location of the access terminal are prioritized for handover preparation. For example, an access terminal may send an indication of its location to its serving access point. The serving access point may determine whether the access terminal is in the vicinity of the access point using the obfuscated identifier based on the location indication. If so, the serving access point may give higher priority to preparing the access point for handover. In some cases, the location of the access terminal may be known based on GPS reports. In some cases, the location of the access terminal may be known based on other access points (including non-macro access points) that the access terminal has visited in the past layers. In these cases, the source may prepare these neighboring and/or previously visited access points, and optionally neighboring access points of the previously visited access points. Thus, in some cases, the access terminal (e.g., the handover controller 320) may receive an indication of whether the access terminal is in the vicinity of the access point and prioritize the identification of block 722 based on the indication. Also, in some cases, the access terminal (e.g., the handover controller 320) may receive an indication of whether the access terminal has previously accessed the access point and prioritize the identification of block 722 based on the indication. Here, the indication may be received, for example, from an access point or other network node (e.g., an access point that each maintains a list of access terminals that have gained access; or a centralized network node that maintains a record of which access points have been accessed by which access terminals).

Referring to block 724 of fig. 7C, once the potential targets are identified, the access point (e.g., the handover controller 320) prepares each of the potential targets for handover. For example, the access point may send a handoff request message to each of these potential targets and receive a corresponding response. Along with this operation, the access point may prepare or obtain handover preparation information for each potential target. This information may include, for example: a temporary identifier (e.g., C-RNTI), security information, and other configuration information common to handover, allocated on each target cell.

The operations of blocks 726 and 744 may be similar to the operations of blocks 622 and 640 of fig. 6, respectively. Therefore, the description of these operations will not be repeated.

As shown at block 746 of fig. 7D, in the event that the desired target is one of the potential targets prepared by the source access point, the handoff can be quickly completed by exchanging a reestablishment message between the target and the access terminal. After releasing the source access point, the handover is completed. In this case, the release of the source access point may serve as an indication to the access point that the time gap has ended.

In the event that the source access point is not prepared for the correct target for handover, the handover process may return to the process of block 642-644 of fig. 6. That is, an unprepared target may initiate a forward handover upon receiving a reestablishment request from an access terminal.

Fig. 8A-8D depict a scenario in which an access point sends handover preparation information to an access terminal regarding preparation of one or more target nodes for handover. In this case, the access terminal may determine whether to allow its access target based on the handover preparation information. This scheme will be described with respect to the following confusion resolution procedure: if the association signal exceeds the threshold, the access terminal reports the first identifier to the access point, then obtains a second identifier (e.g., GCI) upon receiving an indication of an asynchronous time gap from the access point, and then sends a reconfiguration complete message to the target that broadcast the second identifier. Also, it should be appreciated that the disclosure of FIGS. 8A-8D may be applied to other confusion resolution processes that do not include all of the operations described below.

The operations of blocks 802, 820, and 822 may be similar to the operations of blocks 702, 718, 722, and 724, respectively, of fig. 7. Therefore, the description of these operations will not be repeated.

As shown at block 824 of fig. 8C, the access point may send handover preparation information to the access terminal in addition to sending the time gap indication and optionally the reestablishment indication as described above at block 720. For example, the access point (e.g., the handover controller 320) may send handover preparation material described at block 724 corresponding to each target access point prepared for handover at block 822. Along with this information, the access point (e.g., the handover controller 320) may also send a second identifier (e.g., GCI) for each prepared target access point to the access terminal.

The access terminal receives the time gap indication and, in some cases, the reestablishment indication as described above, as shown in block 826. In addition, the access terminal (e.g., handover controller 318) may receive handover preparation information from the source access point. Likewise, the time gap for reading the second identifier may be started upon receiving the time gap indication. As shown at block 828, the access terminal (e.g., identifier controller 322) can monitor transmissions from the target access point during the time gap to obtain the second identifier and optionally the group identifier (e.g., CSGID) as described above. The time gap may be ended when the identifier is obtained (block 830).

As shown at block 832 of fig. 8D, the access terminal (e.g., the handover controller 318) determines whether the target from which the access terminal receives the signal is one of the targets prepared by the source access point. For example, the access terminal may determine whether the identifier received at block 828 matches a corresponding target identifier (e.g., GCI) received with the handover preparation information at block 826.

As shown at blocks 834 and 836, if there is no match (i.e., the desired target is not prepared), the access terminal may return to the process of block 642-644 of fig. 6. That is, if the access terminal is allowed to access the desired target (e.g., as determined above), the access terminal sends a reestablishment request to the desired target. On receipt of this reestablishment request, the unprepared target may initiate a forward handover.

As shown at block 838, if there is a match at block 834, the access terminal (e.g., the handover controller 318) may conduct random access at the target access point and send a reconfiguration complete message to the target. In this case, the access terminal completes the handover using the handover preparation information for the target provided by the source access point. Accordingly, handover may be accomplished more quickly in such a scheme, as additional communication of messages between the access terminal and the target may not be required (block 840). Likewise, the release of the source access point may be used as an indication to the access point to inform that the time gap has ended.

As noted above, the teachings herein may be implemented in a network employing macro access points and femto nodes. Fig. 9 and 10 show examples of how access points may be deployed in such a network. Fig. 9 illustrates, in a simplified manner, how a cell 902 (e.g., macro cell 902A-902G) of a wireless communication system 900 may be served by a corresponding access point 904 (e.g., access points 904A-904G). Here, the macro cell 902 may correspond to the macro coverage area 204 of fig. 2. As shown in fig. 9, access terminals 906 (e.g., access terminals 906A-906L) can be dispersed over time at various locations throughout the system. Each access terminal 906 can communicate with one or more access points 904 on a forward link ("FL") and/or a reverse link ("RL") at a given moment, depending on whether the access terminal 906 is active and whether it is in, for example, soft handoff. Using this cellular scheme, the wireless communication system 900 may provide service over a large geographic area. For example, each of the macrocells 902A-902G may cover multiple blocks of neighborhood or multiple square miles in a rural environment.

Fig. 10 illustrates an example of how one or more femto nodes can be deployed within a network environment (e.g., system 900). In the system 1000 of fig. 10, multiple femto nodes 1010 (e.g., femto nodes 1010A and 1010B) are installed in a network environment with relatively small area coverage (e.g., in one or more user residences 1030). Each femto node 1010 can be coupled to a wide area network 1040 (e.g., the internet) and a mobile operator core network 1050 via a DSL router, cable modem, wireless link, or other connectivity means (not shown).

The owner of the femto node 1010 may subscribe to mobile services, such as 3G mobile services, provided through the mobile operator core network 1050. Further, access terminal 1020 may be capable of operating in both larger environments and in smaller area coverage (e.g., residential) network environments. In other words, depending on the current location of the access terminal 1020, the access terminal 1020 may be served by the macro cellular access point 1060 associated with the mobile operator core network 1050 or by any one of a set of femto nodes 1010 (e.g., femto nodes 1010A and 1010B within a corresponding user residence 1030). For example, a user may be served by a standard macro access point (e.g., access point 1060) when the user is outside his home, and a femto node (e.g., node 1010A) when the user is near or at home. Here, the femto node 1010 may be backward compatible with legacy access terminals 1020.

The femto node 1010 may be deployed on a single frequency or on multiple frequencies. Depending on the particular configuration, a single frequency or one or more of the multiple frequencies may overlap with one or more frequencies used by a macro access point (e.g., access point 1060).

In some aspects, access terminal 1020 may be configured to connect to a preferred femto node (e.g., a home femto node for access terminal 1020) as long as such a connection is possible. For example, it may be desirable for the access terminal 1020A to communicate only with the home femto node 1010A or 1010B as long as the access terminal 1020A is located within the user's residence 1030.

In some aspects, if the access terminal 1020 is operating within the macro cellular network 1050 but not on its most preferred network (e.g., as defined in the preferred roaming list), the access terminal 1020 may continue to search for the most preferred network (e.g., the preferred femto node 1010) with better system reselection ("BSR"), which may involve periodic scanning of available systems to determine whether a better system is currently available, and then attempting to associate with such a preferred system. With the acquisition entry, the access terminal 1020 may limit the search for a particular frequency band and channel. For example, one or more femto channels may be defined whereby all femto nodes (or all restricted femto nodes) in an area operate on the femto channels. The search for the most preferred system may be repeated periodically. Upon discovering a preferred femto node 1010, the access terminal 1020 selects the femto node 1010 to operate within its coverage area.

Femto nodes may be limited in some respects. For example, a given femto node may only provide particular services to particular access terminals. In deployments with what are referred to as restricted (or closed) associations, a given access terminal may be served only by the macro cellular mobile network and a defined set of femto nodes (e.g., femto nodes 1010 within a corresponding user residence 1030). In some embodiments, a node may be restricted to at least one node without providing at least one of: signaling, data access, registration, paging, or traffic.

In some aspects, a restricted femto node (which may also be referred to as a closed subscriber group home node B) is a femto node that serves a restricted set of access terminals. This group can be extended temporarily or permanently when necessary. In some aspects, a closed subscriber group ("CSG") may be defined as a set of access points (e.g., femto nodes) that share a common access control list of access terminals.

Thus, various relationships may exist between a given femto node and a given access terminal. For example, from the perspective of an access terminal, an open femto node may refer to a femto node without restricted association (e.g., a femto node that allows access to any access terminal). A restricted femto node may refer to a femto node that is restricted in some manner (e.g., restricted for association and/or registration). A home femto node may refer to a femto node that authorizes access by and operates on an access terminal (e.g., provides permanent access for a defined set of one or more access terminals). A guest femto node may refer to a femto node that temporarily grants an access terminal access to or operates on. An alien femto node may refer to: a femto node on which an access terminal is not authorized to access or operate on, except for possible emergency situations (e.g., 911 telephone).

From the perspective of a restricted femto node, a home access terminal may refer to an access terminal that is authorized to access the restricted femto node (e.g., an access terminal that has permanent access to the femto node). A guest access terminal may refer to an access terminal that has temporary access rights to a restricted femto node (e.g., a limit based on deadline, time of use, bytes, number of connections, or some other criteria). Foreign access terminals may refer to: access terminals that are not permitted to access the restricted femto node (e.g., access terminals that are not trusted or permitted to register with the restricted femto node), except for possible emergency situations (e.g., 911 telephone).

For convenience, the disclosure herein describes various functionality with respect to a femto node. However, it should be appreciated that a pico node may provide the same or similar functionality for a larger coverage area. For example, a pico node may be restricted, a home pico node may be defined for a given access terminal, and so on.

The teachings herein may be implemented in various types of communication devices. In some aspects, the teachings herein may be implemented in a wireless device that may be deployed in multiple access communication systems that may simultaneously support communication for multiple wireless access terminals. Here, each terminal may communicate with one or more access points via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the access points to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the access points. The communication link may be established by a single-in single-out, multiple-in multiple-out ("MIMO") system, or some other type of system.

To illustrate, fig. 11 depicts example communication components that can be employed in a wireless device in the context of a MIMO-based system 1100. System 1100 employs a plurality (N)_T) Transmitting antenna and a plurality of (N)_R) And the receiving antenna is used for data transmission. May be composed of N_TA transmitting antenna and N_RMIMO channel formed by multiple receiving antennas is decomposed into N_SIndividual channels, also called spatial channels, where N_S≤min{N_T，N_R}。N_SEach of the individual channels corresponds to a dimension. MIMO systems may provide improved performance (e.g., higher throughput and/or greater reliability) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.

System 1100 may support time division duplex ("TDD") and frequency division duplex ("FDD"). In a TDD system, the forward and reverse link transmissions are on the same frequency domain, so the reciprocity principle allows the estimation of the forward link channel from the reverse link channel. This enables the access point to extract transmit beamforming gain on the forward link when multiple antennas are available at the access point.

System 1100 includes a wireless device 1110 (e.g., an access point) and a wireless device 1150 (e.g., an access terminal). At the device 1110, traffic data for a number of data streams is provided from a data source 1112 to a transmit ("TX") data processor 1114.

In some aspects, each data stream is transmitted over a respective transmit antenna. TX data processor 1114 formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot data using OFDM techniques. The pilot data is typically a known data pattern that is processed in a known manner and may be used at the receiver system to estimate the channel response. The multiplexed pilot and coded data for each data stream is then modulated (i.e., symbol mapped) based on a particular modulation scheme (e.g., BPSK, QPSK, M-PSK, or M-QAM) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream may be determined by instructions performed by processor 1130. A data memory 1132 may store program code, data, and other information used by the processor 1130 or other components of the device 1110.

The modulation symbols for all data streams are then provided to a TXMIMO processor 1120, and the modulation symbols may be further processed by the TXMIMO processor 1120 (e.g., for OFDM). The TXMMIMO processor 1120 then processes the N_TA plurality of transceivers ("XCVR") 1122A through 1122T provide N_TA stream of modulation symbols. In some aspects, the TXMIMO processor 1120 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

Each transceiver 1122 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and upconverts) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel. Then respectively from N_TN from transceivers 1122A through 1122T are transmitted by antennas 1124A through 1124T_TModulation ofA signal.

At apparatus 1150, from N_RThe transmitted modulated signals are received by antennas 1152A through 1152R, and the received signal from each antenna 1152 is provided to a respective transceiver ("XCVR") 1154A through 1154R. Each transceiver 1154 conditions (e.g., filters, amplifies, and downconverts) a respective received signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding "received" symbol stream.

A receive ("RX") data processor 1160 then receives and processes data from N based on the particular receiver processing technique_RN of transceivers 1154_RA stream of received symbols to provide N_TA "detected" symbol stream. The RX data processor 1160 then demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor 1160 is complementary to that performed by TX mimo processor 1120 and TX data processor 1114 at device 1110.

A processor 1170 periodically determines which pre-coding matrix to use (as described below). Processor 1170 formulates a reverse link message comprising a matrix index portion and a rank value portion. A data memory 1172 may store program code, data, and other information used by the processor 1170 or other components of the device 1150.

The reverse link message may comprise various types of information regarding the communication link and/or the received data stream. The reverse link message can then be processed by a TX data processor 1138, modulated by a modulator 1180, conditioned by transceivers 1154A through 1154R, and transmitted back to device 1110, the TX data processor 1138 also receives traffic data for a number of data streams from a data source 1136.

At the device 1110, the modulated signals from the device 1150 are received by the antennas 1124, conditioned by the transceivers 1122, demodulated by a demodulator ("DEMOD") 1140, and processed by a RX data processor 1142 to extract the reserve link message transmitted by the device 1150. Processor 1130 then determines which pre-coding matrix to use for determining the beamforming weights then processes the extracted message.

Fig. 11 also shows that the communication components may include one or more components that perform obfuscation control operations as taught herein. For example, the confusion control component 1190 may cooperate with the processor 1130 and/or other components of the device 1110 to send/receive signals to/from another device (e.g., device 1150) as taught herein. Similarly, an obfuscation control component 1192 may cooperate with the processor 1170 and/or other components of the device 1150 to send/receive signals to/from another device (e.g., device 1110). It should be appreciated that for each of devices 1110 and 1150, the functionality of two or more of the described components may be provided by a single component. For example, a single processing component may provide the functionality of the confusion control component 1190 and the processor 1130, and a single processing component may provide the functionality of the confusion control component 1192 and the processor 1170.

The teachings herein may be incorporated into various communication systems and/or system components. In some aspects, the teachings herein may be used in a multiple-access system capable of supporting communication with multiple users by sharing available system resources (e.g., by specifying one or more bandwidths, transmit powers, encoding, interleaving, etc.). For example, the teachings herein may be applied to any one or combination of the following technologies: code division multiple access ("CDMA") systems, multi-carrier CDMA ("MCCDMA"), wideband CDMA ("W-CDMA"), high speed packet access ("HSPA", "HSPA +") systems, time division multiple access ("TDMA") systems, frequency division multiple access ("FDMA") systems, single carrier FDMA ("SC-FDMA") systems, orthogonal frequency division multiple access ("OFDMA") systems, or other multiple access techniques. A wireless communication system employing the teachings herein may be designed to implement one or more standards such as IS-95, CDMA2000, IS-856, W-CDMA, TDSCDMA, and others. A CDMA network may implement a radio technology such as universal terrestrial radio access ("UTRA"), CDMA2000, or some other technology. UTRA includes W-CDMA and low chip rate ("LCR"). cdma2000 technology covers IS-2000, IS-95 and IS-856 standards. TDMA networkTo implement radio technologies such as global system for mobile communications ("GSM"). OFDMA networks may implement methods such as evolved UTRA ("E-UTRA"), IEEE802.11, IEEE802.16, IEEE802.20, and,Etc. radio technologies. UTRA, E-UTRA and GSM are part of the Universal Mobile Telecommunications System ("UMTS"). The teachings herein may be implemented in 3GPP long term evolution ("LTE") systems, ultra mobile broadband ("UMB") systems, and other types of systems. LTE is a release of UMTS that uses E-UTRA. Although particular aspects of the present disclosure may be described using 3GPP terminology, it should be understood that the teachings herein may be applied to 3GPP (Re 199, Re15, Re16, Re 17) technology as well as 3GPP2 (IxRTT, 1xEV-DORelO, RevA, RevB) technology and other technologies.

The teachings herein may be incorporated into (e.g., implemented in or performed by) various devices (e.g., nodes). In some aspects, a node (e.g., a wireless node) implemented in accordance with the teachings herein may comprise an access point or an access terminal.

For example, an access terminal may comprise, be implemented as, or be referred to as user equipment, a subscriber station, a subscriber unit, a mobile station, a mobile device, a mobile node, a remote station, a remote terminal, a user agent, user equipment, or some other terminology. In some implementations, an access terminal may comprise a cellular telephone, a cordless telephone, a session initiation protocol ("SIP") phone, a wireless local loop ("WLL") station, a personal digital assistant ("PDA"), a handheld device having wireless connection capability, or some other suitable processing device connected to a wireless modem. Accordingly, one or more aspects taught herein may be incorporated into a phone (e.g., a cellular phone or smart phone), a computer (e.g., a laptop), a portable communication device, a portable computing device (e.g., a personal data assistant), an entertainment device (e.g., a music device, a video device, or a satellite radio), a global positioning system device, or any other suitable device for communicating over a wireless medium.

An access point may include, be implemented as, or referred to as a node B, eNodeB, a radio network controller ("RNC"), a base station ("BS"), a radio base station ("RBS"), a base station controller ("BSC"), a base transceiver station ("BTS"), a transceiver function ("TF"), a radio transceiver, a radio router, a basic service set ("BSs"), an extended service set ("ESS"), a macrocell, a home eNB ("HeNB"), a femtocell, a femtonode, a picocell, or some other similar term.

In some aspects, a node (e.g., an access point) may comprise an access node for a communication system. For example, such an access node may provide a connection to a network (e.g., a wide area network such as the internet or a cellular network) via a wired or wireless communication link to the network. Thus, an access node may enable another node (e.g., an access terminal) to access a network or some other functionality. Further, it should be appreciated that one or both of the nodes may be portable or, in some cases, relatively non-portable.

Moreover, it should be appreciated that a wireless node may be capable of transmitting and/or receiving information in a non-wireless manner (e.g., via a wired connection). Thus, receivers and transmitters described herein may include appropriate communication interface components (e.g., electrical or optical interface components) to communicate via a non-wireless medium.

The wireless nodes may communicate via one or more wireless communication links based on or supporting any suitable wireless communication technology. For example, in some aspects a wireless node may be associated with a network. In some aspects, the network may comprise a local area network or a wide area network. The wireless device may support or use one or more of a variety of wireless communication technologies, protocols, or standards such as those described herein (e.g., CDMA, TDMA, OFDM, OFDMA, WiMAX, Wi-Fi, etc.). Similarly, the wireless node may support or use one or more of various corresponding modulation or multiplexing schemes. Accordingly, the wireless node may include appropriate components (e.g., air interfaces) to establish and communicate via one or more wireless communication links using the above or other wireless communication techniques. For example, a wireless node may comprise a wireless transceiver with associated transmitter and receiver components, which may include various components (e.g., signal generators and signal processors) that facilitate communication over a wireless medium.

The functionality described herein (e.g., in connection with one or more of the figures) may correspond in some respects to the functionality similarly described as "module for … …" in the appended claims. Referring to fig. 12-16, apparatuses 1200, 1300, 1400, 1500, and 1600 are represented as a series of interrelated functional modules. Here, the message receiving module 1202 may correspond at least in some aspects to, for example, an identifier controller as described herein. The identifier determination module 1204 may correspond at least in some aspects to, for example, a confusion controller as described herein. A messaging module 1206 may correspond at least in some aspects to, for example, a time slot controller as described herein. A request sending module 1208 may correspond at least in some aspects to, for example, an identifier controller as described herein. The identifier receiving module 1210 may correspond at least in some aspects to, for example, an identifier controller as described herein. The identifier usage module 1212 may correspond at least in some aspects to, for example, a handover controller as described herein. The request receiving module 1302 may correspond at least in some aspects to, for example, an identifier controller as described herein. The message receiving module 1304 may correspond at least in some aspects to, for example, a communication controller as described herein. Transmission monitoring module 1306 may correspond at least in some aspects to, for example, a receiver as described herein. Identifier reporting module 1308 can correspond at least in some aspects to, for example, an identifier controller as described herein. The identifier acquisition module 1402 may correspond at least in some aspects to, for example, an identifier controller as described herein. The access determination module 1404 may correspond at least in some aspects to, for example, an access controller as described herein. The reconstruction initiating module 1406 may correspond at least in some aspects to, for example, a handover controller as described herein. The identifier reporting module 1408 may correspond at least in some aspects to, for example, an identifier controller as described herein. The indication receiving module 1410 may correspond at least in some aspects to, for example, a communication controller as described herein. The indication determination module 1412 may correspond at least in some aspects to, for example, a handover controller as described herein. Message receiving module 1502 may correspond at least in some aspects to, for example, an identifier controller as described herein. The identifier determination module 1504 may correspond at least in some aspects to, for example, a confusion controller as described herein. Access point identification module 1506 may correspond at least in some aspects to, for example, a handover controller as described herein. Access point preparation module 1508 may correspond at least in some aspects to, for example, a handover controller as described herein. The information sending module 1510 may correspond at least in some aspects to, for example, a handover controller as described herein. The identifier provision module 1512 may correspond at least in some aspects to, for example, a handover controller as described herein. The indication receiving module 1514 may correspond at least in some aspects to, for example, a handover controller as described herein. The identifier message receiving module 1602 may correspond at least in some aspects to, for example, an identifier controller as described herein. The handover message receiving module 1604 may correspond at least in some aspects to, for example, a handover controller as described herein. The identifier determination module 1606 may correspond at least in some aspects to, for example, a handover controller as described herein. The handover execution module 1608 may correspond at least in some aspects to, for example, a handover controller as described herein. The identifier reporting module 1610 may correspond at least in some aspects to, for example, an identifier controller as described herein. The indication receiving module 1612 may correspond at least in some aspects to, for example, a communication controller as described herein. The probability determination module 1614 may correspond at least in some aspects to, for example, an access controller as described herein. The report determination module 1616 may correspond at least in some aspects to, for example, an identifier controller as described herein.

The functionality of the modules of fig. 12-16 may be implemented in a variety of ways consistent with the teachings herein. In some aspects, the functionality of these modules may be implemented as one or more electronic components. In some aspects, the functions of these blocks may be implemented as a processing system that includes one or more processor components. In some aspects, the functionality of these modules may be implemented, for example, using at least a portion of one or more integrated circuits (e.g., an ASIC). As described herein, an integrated circuit may include a processor, software, other related components, or some combination thereof. The functionality of these modules may also be implemented in some other manner as taught herein. In some aspects, one or more of any of the dashed boxes in fig. 12-16 are optional.

It should be understood that the use of terms such as "first," "second," etc., indicate that any reference to elements herein generally does not limit the number or order of such elements. Rather, these designations may be used herein as a convenient method of distinguishing between two or more elements or instances of an element. Thus, reference to first and second elements does not imply that only two elements may be employed or that the first element must somehow precede the second element. Also, unless otherwise indicated, a set of elements may include one or more elements. Furthermore, an expression in the form of "at least one of a, B or C" as used in the specification or claims means "a or B or C or any combination of these elements. "

Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

Those of skill would further appreciate that any of the various illustrative logical blocks, modules, processors, units, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two, which may be designed using source coding or some other technique), various forms of program or design code containing instructions (which may be referred to herein, for convenience, as "software" or a "software module"), or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed within an integrated circuit ("IC"), an access terminal, or an access point. The IC may include a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, electronic components, optical components, mechanical components, or any combination thereof designed to perform the functions described herein, and may execute code or instructions within the IC, outside of the IC, or both. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

Of course, any specific order or hierarchy of steps in any disclosed process is an example of an exemplary method. Of course, the particular order or hierarchy of steps in the processes may be rearranged depending upon design preferences while remaining within the scope of the present disclosure. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented as software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. As used herein, optical or magnetic disks include Compact Disks (CDs), laser disks, optical disks, Digital Versatile Disks (DVDs), floppy disks, and blu-ray disks where disks usually reproduce data magnetically, while optical disks reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. It should be appreciated that the computer-readable medium may be implemented in any suitable computer program product.

The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (20)

1. A method of communication, comprising:

receiving a first message at an access terminal, wherein the first message comprises an identifier of an access point;

receiving a second message at the access terminal, wherein the second message includes handover preparation information associated with preparation of at least one access point for handover of the access terminal, and wherein the second message further includes at least one identifier of the at least one access point;

determining, at the access terminal, whether the at least one identifier included in the second message includes the identifier of the access point; and

performing, at the access terminal, a handover of the access terminal to the access point based on the determination.

2. The method of claim 1, wherein the performing of the handover uses a portion of the handover preparation information corresponding to the access point if the at least one identifier included in the second message includes the identifier of the access point.

3. The method of claim 1, wherein, if the at least one identifier included in the second message does not include the identifier of the access point, the performing of the handover comprises initiating connection re-establishment at the access point.

4. The method of claim 1, wherein the second message is received from a serving access point of the access terminal.

5. The method of claim 1, wherein the identifier of the access point comprises a global cellular identifier of the access point.

6. The method of claim 1, further comprising:

reporting another identifier of the access point to a serving access point of the access terminal; and

receiving, by the access terminal, an indication of a time gap during which the access terminal may temporarily stop monitoring transmissions from the serving access point in response to the report of the other identifier, wherein the identifier of the access point is acquired during the time gap.

7. The method of claim 6, wherein the identifier of the access point is unique over a larger area than the other identifier.

8. The method of claim 6, wherein the identifier of the access point is more unique than the other identifier, such that identifier confusion is less likely to occur for the identifier of the access point than for the other identifier.

9. The method of claim 6, wherein the indication of the time gap is received with the handover preparation information.

10. The method of claim 6, further comprising:

determining a probability as to whether the access terminal is in the vicinity of the access point and whether the access terminal is allowed to access the access point; and

determining whether to report the other identifier based on the determined probability.

11. An apparatus for communication, comprising:

an identifier controller to receive a first message at an access terminal, wherein the first message includes an identifier of an access point; and

a handover controller configured to receive a second message at the access terminal, wherein the second message comprises handover preparation information associated with preparation of at least one access point for handover of the access terminal, and wherein the second message further comprises at least one identifier of the at least one access point, the handover controller further configured to:

determining, at the access terminal, whether the at least one identifier included in the second message includes the identifier of the access point; and

performing, at the access terminal, a handover of the access terminal to the access point based on the determination.

12. The apparatus of claim 11, wherein the performing of the handover uses a portion of the handover preparation information corresponding to the access point if the at least one identifier included in the second message includes the identifier of the access point.

13. The apparatus of claim 11, wherein the performance of the handover comprises initiating connection re-establishment at the access point if the at least one identifier included in the second message does not include the identifier of the access point.

14. The apparatus of claim 11, wherein:

the identifier controller is further configured to report another identifier of the access point to a serving access point of the access terminal; and is

The apparatus also includes a communication controller to receive an indication of a time gap during which the access terminal may temporarily stop monitoring transmissions from the serving access point in response to the report of the another identifier, wherein the identifier of the access point is acquired during the time gap.

15. The apparatus of claim 14, wherein:

the apparatus also includes an access controller to determine a probability as to whether the access terminal is in proximity to the access point and whether the access terminal is allowed to access the access point; and is

The identifier controller is further configured to determine whether to report the other identifier based on the indication.

16. An apparatus for communication, comprising:

means for receiving a first message at an access terminal, wherein the first message comprises an identifier of an access point;

means for receiving a second message at the access terminal, wherein the second message includes handover preparation information associated with preparation of at least one access point for handover of the access terminal, and wherein the second message further includes at least one identifier of the at least one access point;

means for determining, at the access terminal, whether the at least one identifier included in the second message includes the identifier of the access point; and

means for performing, at the access terminal, a handover of the access terminal to the access point based on the determination.

17. The apparatus of claim 16, wherein the performing of the handover uses a portion of the handover preparation information corresponding to the access point if the at least one identifier included in the second message includes the identifier of the access point.

18. The apparatus of claim 16, wherein the performance of the handover comprises initiating connection re-establishment at the access point if the at least one identifier included in the second message does not include the identifier of the access point.

19. The apparatus of claim 16, further comprising:

means for reporting another identifier of the access point to a serving access point of the access terminal; and

means for receiving, in response to the report of the another identifier, an indication of a time gap during which the access terminal may temporarily stop monitoring transmissions from the serving access point, wherein the identifier of the access point is acquired during the time gap.

20. The apparatus of claim 19, further comprising:

means for determining a probability as to whether the access terminal is in the vicinity of the access point and whether the access terminal is allowed to access the access point; and

means for determining whether to report the other identifier based on the indication.