TW201501477A - Enhanced interference coordination mechanisms for small cell deployments - Google Patents

Abstract

Systems, methods, and instrumentalities are disclosed for coordinating interference in a wireless network characterized by a small cell deployment. A cell may perform state transitions during certain defined times, which may be fixed time instances and/or patterns of state transitions. A wireless transmit/receive unit (WTRU) may be signaled regarding the defined times. A subset of subframes may be configured for CSI measurement and reporting. A time division duplexing (TDD) WTRU may be configured with fixed downlink subframes and flexible downlink subframes, which may be used for uplink transmissions or downlink transmissions. A WTRU may feedback CSI for such flexible downlink subframes. This feedback reporting may enable dynamic power backoff.

Description

Small cell deployment enhances interference coordination mechanism

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to US Provisional Patent Application No. 61/808,074, filed on Apr. 3, 2013, and U.S. Provisional Patent Application No. 61/863,082, filed on August 7, 2013 U.S. Provisional Patent Application No. 61/933,101, filed on Jan. 29, and U.S. Provisional Patent Application No. 61/955,628, filed on March 19, 2014.

[01]

In general, in the 3GPP standard prior to R10, the standard did not know how the WTRU communicated with the Channel State Information (CSI) entity layer feedback report and reference signal reception quality (RSRQ) or reference signal received power (RSRP). The higher layer reports are measured. In R10, a subset subframe is introduced to allow the network to receive higher layer measurements of the feedback report and subset subframes. For example, certain types of patterns are introduced into R10: a subset of subframes assumed to be used for serving cell RSRP measurements, a subset of subframes assumed to be used for RSRP measurements of neighbor cells, and patterns used for CSI measurements. Two subsets.

Typically, prior to LTE Release 11 (R11), the WTRU did not have a designated resource that should be used for measuring interference. The WTRU may filter measurements on the cell-specific reference signal (CRS) to obtain interference values that may be used for CQI determination. In R11, the interference measurement is enhanced. Interference Measurement Resources (CSI-IM) are designated as resources on which the WTRU can measure interference. In a typical deployment, the serving cell may use the ZP CSI-RS on the same RE that it configures the CSI-IM for the WTRU. This ensures that any signal measured on the RE is caused only by interference and noise. Each CSI process is configured with a single CSI-IM and a single CSI-RS. There is no further specification as to how the WTRU should measure interference on such CSI-IMs.

[02]

Interference can be coordinated in a wireless network with small cell deployment. The cell may perform a state transition during certain defined times, which may be a pattern of state transitions and/or a fixed time instance. The time can be communicated to the WTRU for the defined time. Interference measurement results can be reported. The WTRU may be configured with a pattern of different interference periods for CSI feedback and RSRP/RSRQ measurements. These patterns can be configured with CSI-IM and/or CSI processes or can be used in conjunction with CSI-IM and/or CSI processes. A WTRU may be configured with multiple sets of CSI-IM and/or CSI procedures. The WTRU may receive a dynamic indication to determine which CSI-IM and/or CSI process is relevant at any given time. Interference measurements can be reported at RRC based on measuring energy or noise on a set of resources within the subband. [03]

A subset of subframes can be configured for CSI measurement and reporting. A Time Division Duplex (TDD) WTRU may be configured with two types of downlink subframes. Some sub-frames, which may be referred to as fixed downlink sub-frames, may always be considered as downlinks, while other sub-frames, which may be referred to as flexible downlink sub-frames, may sometimes be used for uplink transmission and sometimes Used for downlink transmission. [04]

The WTRU may be configured with channel state information (CSI) resources to perform measurements. The WTRU may feed back the CSI of the fixed downlink, the flexible downlink, or the off subframe. The WTRU may be configured to include measurements for cell state hypotheses (eg, fixed downlink subframe status, flexible downlink subframe status, and/or closed subframe status) in periodic or aperiodic CSI feedback reports. The WTRU may be configured with different CSI procedures for measurement, which may or may not include flexible downlink subframes. For example, the WTRU may be dynamically configured to include measurements made in the flexible downlink subframe in the CSI feedback report.

The feedback report can be assigned dynamic power post shift. The WTRU may be indicated if the subframe is using power back shifting. This indication can be provided dynamically or semi-statically.

[11]

The detailed description can now be described with reference to the drawings. While the description provides specific examples of possible implementations, it should be noted that the specific examples are illustrative and are not intended to limit the scope of the application. [12]

FIG. 1A is a system diagram of an example communication system in which one or more embodiments may be implemented. The communication system 100 can be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple users. Communication system 100 can enable multiple wireless users to access such content via system resource sharing, including wireless bandwidth. For example, the communication system may use one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single Carrier FMDA (SC-FDMA), etc. [13]

As shown in FIG. 1A, communication system 100 can include a wireless transmit/receive unit (WTRU) 102a, 102b, 102c, and/or 102d (which is generally or collectively referred to as a WTRU), a radio access network (RAN). 103/104/105, core network 106/107/109, public switched telephone network (PSTN) 108, internet 110 and other networks 112. It should be understood, however, that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and/or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d may be configured to transmit and/or receive wireless signals, and may include user equipment (UE), base stations, fixed or mobile subscriber units, pagers, mobile phones, individuals Digital assistants (PDAs), smart phones, notebook computers, portable Internet devices, personal computers, wireless sensors, consumer electronics, and more. [14]

The communication system 100 can also include a base station 114a and a base station 114b. Each of the base stations 114a, 114b can be configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the core network 106/107/109, Any device type of the Internet 110 and/or the network 112. As an example, base stations 114a, 114b may be base station transceiver stations (BTS), node B, evolved node B (eNodeB), home node B, home eNB, website controller, access point (AP), wireless Router and so on. While each of the base stations 114a, 114b is depicted as a single component, it should be understood that the base stations 114a, 114b can include any number of interconnected base stations and/or network elements. [15]

The base station 114a may be part of the RAN 103/104/105, and the RAN 104 may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC). , relay nodes, etc. Base station 114a and/or base station 114b may be configured to transmit and/or receive wireless signals within a particular geographic area, which may be referred to as a cell (not shown). Cells can also be divided into cell sectors. For example, a cell associated with base station 114a can be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, one for each sector of a cell. In another embodiment, base station 114a may use multiple input multiple output (MIMO) technology, so multiple transceivers may be used for each sector of the cell. [16]

The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d via the null intermediate plane 115/116/117, which may be any suitable wireless communication link. Road (for example, radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, etc.). The null intermediate plane 116 can be established using any suitable radio access technology (RAT). [17]

More specifically, as noted above, communication system 100 can be a multiple access system and can utilize one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, base station 114a and WTRUs 102a, 102b, 102c in RAN 103/104/105 may use a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) Establish an empty intermediary plane 115/116/117. WCDMA may include, for example, High Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+) communication protocols. HSPA may include High Speed Downlink Packet Access (HSDPA) and/or High Speed Uplink Packet Access (HSUPA). [18]

In another embodiment, base station 114a and WTRUs 102a, 102b, 102c may use a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may use Long Term Evolution (LTE) and/or LTE-Advanced ( LTE-A) to establish an empty intermediate plane 115/116/117. [19]

In other embodiments, base station 114a and WTRUs 102a, 102b, 102c may use, for example, IEEE 802.16 (eg, Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS- 2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), GSM Evolution Enhanced Data Rate (EDGE), GSM EDGE (GERAN), etc. . [20]

The base station 114b in FIG. 1A may be, for example, a wireless router, a home Node B, a home eNodeB, or an access point, and may use any suitable RAT to facilitate localized areas such as a business location, home, vehicle, campus, and the like. Wireless connection in. In one embodiment, base station 114b and WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In another embodiment, base station 114b and WTRUs 102c, 102d may establish a wireless personal area network (WPAN) using a radio technology such as IEEE 802.15. In another embodiment, base station 114b and WTRUs 102c, 102d may use a cellular based RAT (eg, WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.) to establish picocells or femtocells. As shown in FIG. 1A, the base station 114b can have a direct connection to the Internet 110. Thus, base station 114b may not need to access Internet 110 via core network 106/107/109. [twenty one]

The RAN 103/104/105 may be in communication with a core network 106/107/109, which may be configured to provide voice to one or more of the WTRUs 102a, 102b, 102c, 102d Any type of network, such as data, applications, and/or Voice over Internet Protocol (VoIP) services. For example, the core network 106/107/109 can provide call control, billing services, mobile location based services, prepaid calling, internet connectivity, video distribution, etc. and/or perform high level security functions such as user authentication. Although not shown in FIG. 1A, it should be understood that the RAN 103/104/105 and/or the core network 106/107/109 may be associated with other RANs that use the same RAT as the RAN 103/104/105 or different RATs. Direct or indirect communication. For example, in addition to being connected to the RAN 103/104/105 that is using the E-UTRA radio technology, the core network 106/107/109 can also communicate with another RAN (not shown) that uses the GSM radio technology. [twenty two]

The core network 106/107/109 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and/or other networks 112. The PSTN 108 may include a circuit switched telephone network that provides Plain Old Telephone Service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices using public communication protocols, such as Transmission Control Protocol (TCP) in the TCP/IP Internet Protocol Group, User Data Packet Protocol ( UDP) and Internet Protocol (IP). Network 112 may include a wired or wireless communication network that is owned and/or operated by other service providers. For example, the network 112 may include another core network connected to one or more RANs that may use the same RAT as the RAN 103/104/105 or a different RAT. [twenty three]

Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities, for example, the WTRUs 102a, 102b, 102c, 102d may include communications for communicating with different wireless networks over different wireless links. Multiple transceivers. For example, the WTRU 102c shown in FIG. 1A can be configured to communicate with and to communicate with a base station 114a that can use a cellular-based radio technology that can use IEEE 802 radio technology. [twenty four]

FIG. 1B is a system diagram of an example of a WTRU 102. As shown in FIG. 1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a keyboard 126, a display/touchpad 128, a non-removable memory 130, and a removable Memory 132, power source 134, global positioning system (GPS) chipset 136, and other peripheral devices 138. It should be understood that the WTRU 102 may include any sub-combination of the aforementioned elements while remaining consistent with the embodiments. Moreover, embodiments take into account nodes (such as, but not limited to, transceiver stations (BTS), Node B, website controllers, access points (APs), home nodes that base stations 114a and 114b and/or base stations 114a and 114b can represent. B. Evolved Home Node B (eNode B), Home Evolved Node B (HeNB), Home Evolved Node B Gateway and Proxy Node, etc. may include some or all of the elements depicted in FIG. 1B and described herein. [25]

The processor 118 can be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with the DSP core, a controller, and a micro Controllers, Dedicated Integrated Circuits (ASICs), Field Programmable Gate Array (FPGA) circuits, any other type of integrated circuit (IC), state machine, and more. The processor 118 may perform signal encoding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 can be coupled to a transceiver 120 that can be coupled to the transmit/receive element 122. Although FIG. 1B depicts processor 118 and transceiver 120 as separate components, it should be understood that processor 118 and transceiver 120 may be integrated together in an electronic package or wafer. For example, the processor of processor 118 may include integrated memory (eg, WTRU 102 may include a chipset that includes a processor and associated memory). Memory may refer to memory integrated with a processor (eg, processor 118) or memory associated with a device (eg, WTRU 102). Memory can be non-permanent. The memory can include (eg, store) instructions (eg, software and/or firmware instructions) executable by the processor. For example, memory can include instructions that, when executed, can cause a processor to implement one or more implementations described herein. [26]

The transmit/receive element 122 can be configured to transmit signals to or from a base station (e.g., base station 114a) via the null planes 115/116/117. For example, in one embodiment, the transmit/receive element 122 can be an antenna configured to transmit and/or receive RF signals. In another embodiment, the transmit/receive element 122 may be a transmitter/detector configured to transmit and/or receive IR, UV or visible light signals, for example. In another embodiment, the transmit/receive element 122 can be configured to transmit and receive both RF and optical signals. It should be understood that the transmit/receive element 122 can be configured to transmit and/or receive any combination of wireless signals. [27]

Additionally, although the transmit/receive element 122 is depicted as being single in FIG. 1B, the WTRU 102 may include any number of transmit/receive elements 122. More specifically, the WTRU 102 may use, for example, MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmission/reception elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via the null intermediaries 115/116/117. [28]

The transceiver 120 can be configured to modulate signals to be transmitted by the transmit/receive element 122, and/or demodulate signals received by the transmit/receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, transceiver 120 may include multiple transceivers that cause WTRU 102 to communicate via multiple RATs, such as UTRA and IEEE 802.11. [29]

The processor 118 of the WTRU 102 can be coupled to the following devices and can receive user input data from: a speaker/microphone 124, a keyboard 126, and/or a display/touchpad 128 (eg, a liquid crystal display (LCD)) Display unit or organic light emitting diode (OLED) display unit). The processor 118 can also output user data to the speaker/microphone 124, the keyboard 126, and/or the display/trackpad 128. Additionally, processor 118 can access information from any type of suitable memory and can store the data into any type of suitable memory, such as non-removable memory 130, removable memory 132, and/or A memory integrated with the processor 118. Non-removable memory 130 may include random access memory (RAM), read only memory (ROM), hard disk, or any other type of memory device. The removable memory 132 can include a Subscriber Identity Module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from memory that is not located at the physical location on the WTRU 102 (eg, located on a server or a home computer (not shown), and may store the data in the memory. In the body. [30]

The processor 118 can receive power from the power source 134 and can be configured to allocate and/or control power to other elements in the WTRU 102. Power source 134 can be any suitable device that powers WTRU 102. For example, the power source 134 may include one or more dry cells (eg, nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), solar cells, fuel cells, etc. Wait. [31]

The processor 118 may also be coupled to a GPS chipset 136 that may be configured to provide location information (eg, longitude and latitude) regarding the current location of the WTRU 102. Additionally, in addition to or in lieu of information from GPS chipset 136, WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) via null intermediaries 115/116/117 and/or based on two or The timing of the signals received by more neighboring base stations determines their position. It should be understood that the WTRU 102 may obtain location information using any suitable location determination method while maintaining consistency of implementation. [32]

The processor 118 can be coupled to other peripheral devices 138, which can include one or more software and/or hardware modules that provide additional features, functionality, and/or wired or wireless connections. For example, peripheral device 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photo or video), a universal serial bus (USB) port, a vibrating device, a television transceiver, a hands-free headset, Bluetooth (Bluetooth) ®) Modules, FM radio units, digital music players, media players, video game console modules, Internet browsers, and more. [33]

1C is a system diagram of RAN 103 and core network 106, in accordance with an embodiment. As mentioned above, the RAN 103 can use UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c via the null plane 115. The RAN 103 can also communicate with the core network 106. As shown in FIG. 1C, RAN 103 may include Node Bs 140a, 140b, 140c, each of Node Bs 140a, 140b, 140c including one or more for communicating with WTRUs 102a, 102b, 102c via null mediation plane 115. Transceivers. Each of Node Bs 140a, 140b, 140c can be associated with a particular cell (not shown) within RAN 103. The RAN 103 may also include RNCs 142a, 142b. It should be understood that the RAN 103 may include any number of Node Bs and RNCs while maintaining consistency of implementation. [34]

As shown in FIG. 1C, Node Bs 140a, 140b can communicate with RNC 142a. Additionally, Node B 140c can communicate with RNC 142b. Node Bs 140a, 140b, 140c can communicate with RNCs 142a, 142b via Iub interfaces, respectively. The RNCs 142a, 142b can communicate with each other via the Iur interface. Each of the RNCs 142a, 142b can be configured to control the respective Node Bs 140a, 140b, 140c to which they are connected. Additionally, each of the RNCs 142a, 142b can be configured to perform or support other functions, such as outer loop power control, load control, admission control, packet scheduling, handover control, macro diversity, security functions, data encryption, and the like. [35]

The core network 106 shown in FIG. 1C may include a media gateway (MGW) 144, a mobile switching center (MSC) 146, a serving GPRS support node (SGSN) 148, and/or a gateway GPRS support node (GGSN). While each of the foregoing elements is described as being part of core network 106, it should be understood that any of these elements may be owned or operated by an entity that is not a core network operator. [36]

The RNC 142a in the RAN 103 can be connected to the MSC 146 in the core network 106 via an IuCS interface. The MSC 146 can be connected to the MGW 144. MSC 146 and MGW 144 may provide WTRUs 102a, 102b, 102c with access to a circuit-switched network (e.g., PSTN 108) to facilitate communications between WTRUs 102a, 102b, 102c and conventional landline communications devices. [37]

The RNC 142a in the RAN 103 may also be connected to the SGSN 148 in the core network 106 via the IuPS interface. The SGSN 148 can be connected to the GGSN 150. The SGSN 148 and GGSN 150 may provide the WTRUs 102a, 102b, 102c with access to a packet switched network (e.g., the Internet 110) to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. [38]

As noted above, core network 106 can also be coupled to network 112, which can include other wired or wireless networks that are owned or operated by other service providers. [39]

FIG. 1D is a system diagram of the RAN 104 and the core network 107 in accordance with an embodiment. As mentioned above, the RAN 104 may use E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c via the null plane 116. The RAN 104 can also communicate with the core network 107. [40]

The RAN 104 may include eNodeBs 160a, 160b, 160c, although it will be appreciated that the RAN 104 may include any number of eNodeBs to maintain consistency with various embodiments. Each of the eNBs 160a, 160b, 160c may include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c via the null plane 116. In one embodiment, the eNodeBs 160a, 160b, 160c may use MIMO technology. Thus, eNodeB 160a, for example, may use multiple antennas to transmit and/or receive wireless signals to and from WTRU 102a. [41]

Each of the eNodeBs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, user scheduling in the uplink and/or downlink and many more. As shown in FIG. 1D, the eNodeBs 160a, 160b, 160c can communicate with each other via the X2 interface. [42]

The core network 107 shown in FIG. 1D may include a Mobility Management Entity (MME) 162, a Serving Gateway 164, and/or a Packet Data Network (PDN) Gateway 166. While each of the foregoing elements is described as being part of core network 107, it should be understood that any of these units may be owned and/or operated by entities other than the core network operator. [43]

The MME 162 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via the S1 interface and may serve as a control node. For example, the MME 162 may be responsible for user authentication of the WTRUs 102a, 102b, 102c, bearer activation/deactivation, selection of a particular service gateway during initial connection of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may also provide control plane functionality for switching between the RAN 104 and other RANs (not shown) using other radio technologies such as GSM or WCDMA. [44]

Service gateway 164 may be connected to each of eNBs 160a, 160b, 160c in RAN 104 via an S1 interface. The service gateway 164 can typically route and forward user data packets to/from the WTRUs 102a, 102b, 102c. The service gateway 164 may also perform other functions, such as anchoring the user plane during inter-eNB handovers, triggering paging, managing and storing the context of the WTRUs 102a, 102b, 102c when the downlink information is available to the WTRUs 102a, 102b, 102c (context) )and many more. [45]

The service gateway 164 may also be connected to a PDN gateway 166 that may provide the WTRUs 102a, 102b, 102c with access to a packet switched network (e.g., the Internet 110) to facilitate the WTRUs 102a, 102b, Communication between 102c and the IP-enabled device. [46]

The core network 107 can facilitate communication with other networks. For example, core network 107 may provide WTRUs 102a, 102b, 102c with access to a circuit-switched network (e.g., PSTN 108) to facilitate communications between WTRUs 102a, 102b, 102c and conventional landline communications devices. For example, core network 107 may include or be in communication with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between core network 107 and PSTN 108. In addition, core network 107 can provide access to network 112 to WTRUs 102a, 102b, 102c, which can include other wired or wireless networks that are owned and/or operated by other service providers. [47]

FIG. 1E is a system diagram of the RAN 105 and the core network 109 in accordance with an embodiment. The RAN 105 may be an Access Service Network (ASN) that communicates with the WTRUs 102a, 102b, 102c via the null plane 117 using IEEE 802.16 radio technology. As discussed further below, the links between the different functional entities of the WTRUs 102a, 102b, 102c, RAN 105, and core network 109 may be defined as reference points. [48]

As shown in FIG. 1E, the RAN 105 may include base stations 180a, 180b, 180c and ASN gateway 182, although it should be understood that the RAN 105 may include any number of base stations and ASN gateways consistent with the embodiment. Each of the base stations 180a, 180b, 180c may be associated with a particular cell (not shown) in the RAN 105 and may include one or more transceivers that communicate with the WTRUs 102a, 102b, 102c via the null mediation plane 117. In one embodiment, base stations 180a, 180b, 180c may use MIMO technology. Thus, base station 180a, for example, uses multiple antennas to transmit wireless signals to, or receive wireless signals from, WTRU 102a. Base stations 180a, 180b, 180c may provide mobility management functions such as handoff triggering, tunnel establishment, radio resource management, traffic classification, quality of service policy enforcement, and the like. The ASN gateway 182 can act as a traffic aggregation point and is responsible for paging, caching user profiles, routing to the core network 109, and the like. [49]

The null interfacing plane 117 between the WTRUs 102a, 102b, 102c and the RAN 105 may be defined as an Rl reference point using the 802.16 specification. In addition, each of the WTRUs 102a, 102b, 102c can establish a logical interface (not shown) with the core network 109. The logical interface between the WTRUs 102a, 102b, 102c and the core network 109 can be defined as an R2 reference point that can be used for authentication, authorization, IP host configuration management, and/or mobility management. [50]

The communication link between each of the base stations 180a, 180b, 180c may be defined as an R8 reference point that includes a protocol that facilitates WTRU handover and transfer of data between base stations. The communication link between base stations 180a, 180b, 180c and ASN gateway 182 may be defined as an R6 reference point. The R6 reference point may include an agreement to facilitate mobility management based on mobility events associated with each of the WTRUs 102a, 102b, 102c. [51]

As shown in FIG. 1E, the RAN 105 can be connected to the core network 109. The communication link between the RAN 105 and the core network 109 can be defined as an R3 reference point that includes, for example, protocols that facilitate data transfer and mobility management capabilities. The core network 109 may include a Mobile IP Home Agent (MIP-HA) 184, an Authentication, Authorization, Accounting (AAA) server 186, and a gateway 188. While each of the foregoing elements are described as being part of core network 109, it should be understood that any of these elements may be owned or operated by an entity that is not a core network operator. [52]

The MIP-HA may be responsible for IP address management and may cause the WTRUs 102a, 102b, 102c to roam between different ASNs and/or different core networks. The MIP-HA 184 may provide the WTRUs 102a, 102b, 102c with access to a packet switched network (e.g., the Internet 110) to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The AAA server 186 can be responsible for user authentication and support for user services. Gateway 188 facilitates interworking with other networks. For example, the gateway may provide access to the circuit switched network (e.g., PSTN 108) to the WTRUs 102a, 102b, 102c to facilitate communication between the WTRUs 102a, 102b, 102c and conventional landline communication devices. In addition, gateway 188 can provide network 112 to WTRUs 102a, 102b, 102c, which can include other wired or wireless networks that are owned or operated by other service providers. [53]

Although not shown in Figure 1E, it should be understood that the RAN 105 can be connected to other ASNs and the core network 109 can be connected to other core networks. The communication link between the RAN 105 and other ASNs may be defined as an R4 reference point, which may include a protocol that coordinates the mobility of the WTRUs 102a, 102b, 102c between the RAN 105 and other ASNs. The communication link between core network 109 and other core networks may be defined as an R5 reference point, which may include an agreement to facilitate interworking between the local core network and the visited core network. [54]

Dense cell deployment can increase throughput gain by increasing cell splitting. However, this gain may be ineffective due to increased inter-cell interference. Moreover, cell behavior can be dynamic; for example, cells can switch from active to dormant, can coordinate the use of resources with other cells, or they can dynamically switch time-division duplex (TDD) configurations. In this scenario, the interference scene can change rapidly. Some problems may arise due to dynamic and sharp changes in the disturbance. For example, the WTRU may filter interference measurements on multiple subframes. However, if the WTRU does not know the change in possible interference from neighboring cells, its filtering may be sub-optimal and may reduce the possible throughput. Moreover, considering that the cell may not be able to know what assumptions the WTRU uses to obtain its feedback report, the cell may not be able to apply effective link adaptability. [55]

Another problem is that the IMR may be configured by RRC messaging, so the reconfiguration may be too slow to accommodate the interference scene change. [56]

Densely deployed cells may use a subset of resources (eg, sub-frames, PRBs, and/or subsets of transmit beams) to mitigate inter-cell interference. In such cases, it may be unclear how the WTRU should adjust its feedback to better represent the channel characteristics of the applicable subset of resources. [57]

Densely deployed cells can operate in different states. For example, some cells may be active while others may be dormant. It may be beneficial to have the WTRU be served by a cell that is not its optimal cell to allow certain cells to be turned off and to limit the total interference. To achieve this, load transfer can be used. If the WTRU does not know the status of the neighbor cell, the WTRU's serving cell and neighbor cell measurements may result in an incorrect reporting trigger. Methods and conditions that limit unnecessary reporting triggers can be implemented on different cells. [58]

There is a fixed instance of time when a cell can perform state transitions. The time instance may be indicated to the WTRU statically or dynamically to illustrate that the WTRU is performing appropriate channel state information (CSI) feedback. In addition, there is a state transition pattern. These patterns ensure that a particular state transition occurs at a predetermined time. [59]

The WTRU may be configured with a pattern of different interference periods for CSI feedback and RSRP/RSRQ measurements. These patterns can be configured with CSI-IM and/or CSI processes or can be used in conjunction with CSI-IM and/or CSI processes. [60]

A WTRU may be configured with multiple sets of CSI-IM and/or CSI procedures. The WTRU may receive a dynamic indication to determine which CSI-IM and/or CSI process set is relevant at any given time. [61]

A WTRU may be configured to expect to receive on a subset of resources that may change dynamically. In this case, the WTRU may adjust its measurements to uniquely apply to the subset of resources. For example, broadband measurements can be applied only to a subset of resources. [62]

The cell deviation of the RSRP/RSRQ measurements can be dynamically signaled. The measurement report can be triggered when the collection of cells has new elements to report. The report can include the RSRP for all elements of the collection. [63]

New interference measurements can be reported at RRC based on measuring energy or interference on a set of resources within the subband. It can be triggered based on the detection side to interference within the sub-band becoming better or worse than within the other sub-band. [64]

One or more triggers can be defined for higher level reporting of interference. [65]

Signal to noise plus interference ratio (SINR) measurements can be defined; this SINR measurement can be reported by the WTRU to facilitate enhanced cell association. [66]

A channel state information (CSI) report of one or more subsets of resources may be capable of reporting different broadband values, possible correlations for multiple subsets of resources. [67]

The feedback report may enable adaptive downlink (DL) power control. The WTRU may send a feedback report that may allow the small cell configuration to optimize its transmission, for example, to reduce interference. The small cells can exchange the traffic load associated with the enhanced small cells. [68]

The state transition of a cell can refer to any parameter of a cell or a change in a defined property. For example, a state transition can involve any of a variety of changes in the state of one or more cells. For example, a state transition may involve one or more cells switching from a sleep mode to an active mode, or vice versa. State transitions may involve one or more cell changes to a time division duplex (TDD) configuration. State transitions may involve one or more cells changing from one set of possible transmission or reception resources to another set or changing the carrier type. State transitions may involve any other variation in the downlink or uplink transmission that can affect the performance of neighbor cells. The WTRU's channel measurements can be affected when state transitions occur in nearby cells. [69]

To limit the possible time instances when the interference scene may change dramatically, the network configurable cell has the ability to perform state transitions only at certain times (eg, system subframe number, SFN). If the state transfer is not necessary, the small cell does not have to perform a state transition at that time. Once configured, each cell can assume that its neighbor cells share the same set of possible state transition times. The cell may also be configured with a set of possible state transition times of neighbor cells. Cell clusters can be defined, and each cell within the cluster can be configured to share the same set of possible state transition times. [70]

The configuration of cells with one or more suitable sets of possible state transition times may occur (eg, via the X2 interface) or may originate from a macro cell, a cluster controller entity, or a neighbor cell. The configuration from neighbor cells can be a request or recommendation, which can give the target cell the ability to accept or reject the suggested set of possible state transition times. [71]

The WTRU itself served by the cells that have been configured with the set of possible state transition times may be configured with the set or any other set of serving cells or networks that are deemed necessary for proper operation of the WTRU. The WTRU may be configured with a set of possible state transition times for neighbor cells. This configuration can be done via a higher layer such as RRC. [72]

A WTRU configured with a set of possible state transition times may assume that the measurements are accumulated until there is little or no relationship between the possible state transition times and subsequent measurements. These measurements may include, for example, RSRP, RSRQ, RI, CQI, and/or PMI. [73]

The set of possible state transition times that may be received by another cell or WTRU may be configured to indicate a bitmap of the subframe or frame in which the state transition may occur. The set of possible state transition times may be communicated as a binary representation of one or more subframes and/or actual SFNs in which the transfer may occur. The set of possible state transition times can be implicitly determined. For example, a possible set of state transition times may be obtained from a pre-configured cluster ID or a PCI of a serving cell. The set of possible state transition times may be obtained from the RNTI configured for the WTRU. [74]

The set of possible state transition times may cover the exact time period and may be updated at the end of the exact time period. For example, after the entire period of the SFN, a new set of possible state transition times can be configured. If the cell or WTRU is not configured with a new set at that time, the cell or WTRU may assume that the state transition is assumed to not occur again. A cell or WTRU that is not configured with a new set at the end of the period may assume that the previous configuration should be used again (eg, continue to be valid). The set may be assumed to be valid until another configuration removes any of the assumptions or provides a new set of state transition times to the cell or WTRU. [75]

The WTRU may be dynamically notified of the upcoming possible state transition time. Upon receiving a dynamic indication that a possible state transition may occur in subframe n , the WTRU may assume that the possible state transition actually occurs in subframe n+k , where k is pre-configured. The dynamic indication can be transmitted via an information element in a Downlink Control Information (DCI) format or in a MAC message. The DCI format can be used with cell or cluster specific scrambling codes to indicate that a possible state transition time will occur. Some or all of the WTRUs served by the cell or by the entire cluster may be configured with the scrambling code to enable the WTRUs to determine the possible state transition time from the broadcast type message. [76]

In order to reduce the decoding requirements of the WTRU in a cell in which the state transition time can be dynamically communicated, the resources on which the WTRU may receive the DCI may be pre-configured, for example, as a cell-specific search space. The period of the resource may be multiple subframes to reduce WTRU decoding complexity. [77]

Resources in which the DCI can be included can be pre-configured via higher layer messaging. The resources in which the DCI can be included can be determined based on the cell ID and/or the cluster ID. [78]

A dynamic indication of possible state transition times may be obtained from the CSI request timing and applicable to the corresponding aperiodic CSI report. This dynamic indication can also be applied to future aperiodic or periodic CSI report instances. [79]

The WTRU may acknowledge receipt of the state transition indication by using a bit flag in subsequent reporting instances such as its next periodic or aperiodic. [80]

The WTRU may independently determine interference variations as it performs its configuration measurements. For example, the WTRU may measure the instantaneous interference for each appropriate subframe and, if it is possible that the change in the continuous instantaneous interference measurement is greater than the threshold, the WTRU may independently determine that the state transition time has occurred. To facilitate independent determination, the WTRU may be configured with a threshold. The threshold may be configured by a higher layer (eg, RRC) or dynamically configured by the entity layer. When the interference measurement changes at least the threshold, the WTRU may assume that a state transition has occurred. Once the WTRU determines that a state transition has occurred, the WTRU may inform the serving cell of the state transition. The WTRU may include an indication, such as a single bit flag, in a periodic or aperiodic reporting instance. [81]

The WTRU may determine a set of frames or subframes in which different levels of interference are seen (eg, if the difference is greater than a pre-configured threshold). The WTRU may report a frame or a collection of subframes to the network. Moreover, if the WTRU determines that two or more sets of subframes or subframes have different levels of interference, the WTRU may be configured to adjust its aperiodic report to include two or more sets of CSI feedback. [82]

The WTRU may perform measurements on interference measurement resources or on a set of interference measurement resources configured by higher layers, and report measurements at higher layers such as RRC. This measurement report can be used by the network to assist in coordinating resource usage between cells. [83]

The measuring can include measuring received power (or energy) in at least one resource block (PRB) and at least one resource element (RE) of the at least one subframe or PRB pair. The value can be an average over at least one RE, subframe, and PRB, and has a logarithmic or linear unit (eg, dBm or mW). The measurement can include an estimate of the noise power added to the known signal. The measurement can include an estimate of the signal to noise ratio of the known signal. This measurement can replace the RSSI in the RSRQ measurement, where the RSRP measurement can be performed, for example, on the discovery signal rather than the cell-specific reference signal. [84]

The set of REs from which the measurements are obtained may be defined as a particular set of REs in the PRB, a particular set of subframes, and/or a particular set of PRBs. The set of REs in the PRB may be represented by, for example, a CSI-RS resource configuration. The subframe set can be represented by a CSI-RS subframe configuration. The subframe set may be limited to a time period, for example, if the WTRU is known, the period may begin at the last state transition time, or after receiving a physical layer communication or MAC indicating a resource change for interference measurement. [85]

A PRB set can be defined as a continuous or non-contiguous set of PRBs within a carrier. For example, the PRB set may be consistent with the set of PRBs corresponding to the subbands in the CSI report. For example, a PRB set can be explicitly configured using a bit map. The PRB set may include a PRB of a carrier (eg, all PRBs). [86]

The set of resources on which interference measurements are performed may be configured by higher layers using the configurations disclosed herein. The CSI-IM configuration for CSI reporting can implicitly define a set of interference measurements. A set of interference measurements for the configuration of the set of REs and subframes may be implicitly defined. Interference measurements for subbands outside of the predefined subband set (eg, subbands used in CSI reports) may be defined. Broadband measurements for the carrier can be defined. If the measurement includes an estimate of the noise added to the known signal, the WTRU may be configured with information for determining the known signal, eg, a non-zero power CSI-RS configuration. [87]

A WTRU may be pre-configured with multiple sets of resources for interference measurements. The WTRU may be informed from the MAC or entity layer (e.g., downlink control information) a particular set of interference measurements that are used and that are outside of the pre-configured set. [88]

The WTRU may maintain at least one set of subbands for at least the purpose of event reporting. For example, a high quality subband set can be maintained, and/or a low quality subband set can be maintained. These sets may be configured from a higher layer or may be autonomously updated by the WTRU based on the triggering of certain reports. The set may correspond to a resource in which the WTRU may report CSI. [89]

The WTRU may trigger a report of interference measurements for the interference measurement set, at least when one of the multiple events occurs. After expiration of the timer initiated when the report was last triggered, the WTRU may trigger a report of the interference measurement. The WTRU may trigger reporting of interference measurements at a pre-configured time (e.g., as indicated by higher layer signals). If the WTRU is aware, the WTRU may trigger a report on the interference measurement after a fixed delay after the start of the state transition. After receiving a fixed delay after MAC or entity layer messaging indicating a state transition or resource change, the WTRU may trigger a report on the interference measurement. The WTRU may trigger reporting of interference measurements as soon as the interference level exceeds one subband or across multiple subbands (eg, all subbands). If (eg, if only) the subband is part of a set of subbands (eg, high quality subbands) or if (eg, only if) the subband is not part of a set of subbands (eg, low quality subbands), This trigger can occur. The WTRU may then remove the subband from the high quality subband set or add the subband to the low quality subband set. The WTRU may trigger a report of interference measurements as soon as the side-to-interference level drops below one subband or across multiple subbands (eg, all subbands). If (eg, if only) the subband is part of a set of subbands (eg, low quality subbands), or if (eg, if only) the subband is part of a set of subbands (eg, high quality subbands) , the trigger can occur. The WTRU may then remove the subband from the low quality subband set or add the subband to the high quality subband set. [90]

The WTRU may trigger reporting of interference measurements as soon as the interference level of the first sub-band of the interception becomes higher than the interference level of the second sub-band plus the offset. If (eg, if only) the first sub-band is part of a high quality sub-band set and the second sub-band is not part of a high quality sub-band set, or if (eg, if only) the first sub-band is not a low quality sub-band The triggering can occur as part of the set and the second sub-band is part of a low-quality sub-band set. The WTRU may then remove the first subband from the high quality subband set and may add the second subband to the high quality subband set, or may add the first subband to the low quality subband set and may The two subbands are removed from the low quality subband set. This can occur if (eg, only if) the second sub-band is the previous sub-band with the highest interference level. This can occur if (eg, only if) the first sub-band is the previous sub-band with the lowest interference level. [91]

The WTRU may trigger a report for measuring the interference report once the interference to the interference measured on the first set of resources exceeds the interference measured on the second set of resources plus the offset. This trigger can occur if (eg, only if) the measurements on the second set of resources are initially the largest and/or smallest interference measurements. This trigger may occur if (eg, if only) measurements on the second set of resources were previously reported as maximum and/or minimum interference measurements. This trigger may occur if (eg, if only) the measurements on the second set of resources are initially part of the measurement report set and the measurements on the first set of resources are not part of the measurement report set. This trigger may occur if, for example, only if the measurements were reported by the WTRU before the measurements on the first and second sets of resources. [92]

A measurement report triggered according to one of the conditions disclosed herein may include interference measurements for a set of subbands or across all subbands (eg, wideband). The set may be defined as a sub-band corpus for which the measurement is defined, or may only include sub-bands of interest to the trigger. [93]

The measurement report may alternatively or additionally include interference measurements for the set of interference measurement resources, each of which may be a broadband or sub-band measurement. The set may be configured by higher layer messaging or may be configured by dynamic messaging on physical layer resources. The set may be determined by the WTRU as a measurement that meets certain pre-configured criteria. For example, the WTRU may report interference measurements for any resource that falls within a critical value from the maximum or minimum interference measurements. The WTRU may report interference measurements for the best or worst x resources, where x is pre-configured. [94]

The measurement report may alternatively or alternatively include RSRP measurements for at least the same frequency (eg, measurement object) as the resource used for the interference measurement. [95]

The measurement report may alternatively or alternatively include similar RSRQ measurements of at least the same frequency (eg, measurement object) that can be used for the interference measurement. This interference measurement can be reused again like RSSI measurements. [96]

The measurement report may alternatively or alternatively include a signal to interference and noise ratio (SINR) measurement of all or a subset of the configured resources. The SINR may be obtained as one or more of a plurality of values. The SINR can be obtained as a combination of RSRP and interference measurements. The combination of resources for RSRP and interference measurements can be pre-configured. For example, a WTRU may be configured with a list of resources on which RSRP measurements or equivalent expected signal power are performed and another list of resources on which interference measurements are made. The WTRU may be configured with a measurement report indicating the combination of interference and RSRP or equivalent desired signal power required to obtain the desired SINR measurement. The WTRU may be configured with a list of SINR resources. The elements in the list may include a set of resources on which the RSRP or equivalent desired signal power is measured and a set of resources over which the interference is measured. [97]

The measurement report may alternatively or also include values obtained from a single resource. The WTRU may obtain RSRP or equivalent expected signal power and interference values on the same set of resources, and may obtain SINR measurements for each measurement resource. [98]

The measurement report may alternatively or alternatively include a ratio of the desired signal power to the sum of the interference power plus the offset term. The offset term in the denominator of the SINR may represent the measurement of interference and noise to the out-of-macro-cell-area. [99]

The measurement report may alternatively or alternatively include a combination of the RSRP value for the desired signal and the RSRP value used as the interference signal. For example, a WTRU may be configured to perform RSRP measurements on multiple resources. The WTRU may be configured with SINR feedback. The configuration may indicate to the WTRU the RSRP that is assumed to be the desired signal for each SINR measurement and the RSRP value list that is used as the interference signal. Another power measurement can be used to replace the RSRP measurement or as an addition to the RSRP measurement. This power measurement can be performed over a portion of the bandwidth in the entire bandwidth. [100]

To reduce complexity, cells may not be allowed to switch states more than once per predetermined number of frames. A specific pattern of state transitions can be configured. The number of state transition patterns can be limited. The pattern can force the cell to switch states at the appropriate time. For example, if a cell can be allowed to switch between state A and state B, as shown in Figure 2, the cell may be able to do so in a limited number of patterns. This can limit the number of state transition instances throughout the network and can also enable different cells to better configure their WTRUs for measurement reports. Moreover, by ensuring that the cell switches state during the pre-configured time, the method can reduce the uncertainty involved in allowing each cell to independently determine its state in a fully dynamic manner regardless of whether the switch is at a pre-configured time. [101]

The neighbor cell shares its state transition pattern with its neighbors. Moreover, depending on the configuration of the pattern, the cell can transmit (eg, via the X2 interface) the pattern to its neighbors. For example, cells may also recommend patterns to neighbor cells to limit any negative effects on their WTRU's operation. [102]

The WTRU may be configured with one or more patterns of different interference periods. The pattern is selected at the serving cell according to a combination of state transition patterns such as neighbor cells. In this example, the state transition occurs at a predetermined time. Moreover, if the serving cell is aware of the WTRU's primary interferer, the appropriate interference period pattern can be configured (eg, optimal) for the WTRU. The WTRU may use explicit feedback (e.g., a list of interferers) to indicate its primary interferer to its serving cell, or may implicitly indicate its primary interferer by, for example, a neighboring element RSRP list. [103]

The serving cell can use this information to enable it to configure the appropriate CSI-IM and/or CSI procedures. WTRUs with different CSI-IM and/or CSI procedures may be assigned such that the CSI-IM/CSI procedure is defined to occur only in subframes/frames where similar interference levels are desired. However, a WTRU may have a limited number of possible CSI-IM configurations. [104]

The CSI-IM and/or CSI process can be configured with its own interference cycle pattern. This configuration may be done via a higher layer or may be a new information element in current CSI-IM and/or CSI process configurations. Moreover, the CSI-IM and/or CSI process can be configured to interfere with the periodic pattern. This reconfiguration may not involve full reconfiguration of the CSI-IM and/or CSI processes. [105]

The CSI-IM and/or CSI processes can be configured with the same interference period pattern. This pattern or measurement mask can be used to enable the WTRU to determine what type of filter is being used in measurements made for interference for all CSI processes. [106]

When using the pattern of each CSI-IM and/or CSI process, the WTRU may also be configured to have an explicit relationship between the interference period and the periodic and/or aperiodic reporting instances. For example, if a disturbance n subframe period ends, in subframe n + k or longer period or aperiodic reporting instance may be assumed that a new period of the interference. [107]

The interference period of some or all of the CSI-IM and/or CSI processes can be dynamically indicated. This dynamic indication may have a list of CSI-IM and/or CSI procedures (eg, by using a CSI process index), and the WTRU may assume that a new interference period for the CSI-IM and/or CSI procedure has begun. This dynamic indication can be performed as an implicit relationship with another configuration. For example, WTRV can be configured with a new cell state. Each state of the cell can be associated with a different interference hypothesis. The cell state indication may implicitly configure the interference period for the CSI-IM and/or CSI process for the WTRU. [108]

The timing of the WTRU's feedback report can determine which of the previous measurement resources it can take into account. For example, the feedback report in subframe n may be based on the CSI reference resource in subframe nk ₁ . Moreover, the measurement applicable to the CSI reference resources in the subframe nk ₁ may additionally depend only on any measurements made in the subframes nk ₂ , nk ₃ , nk ₄ ..., nk _j . The value of k ₂ , k ₃ , k ₄ , . . . k _j may be configured for the WTRU and may depend on the value of n or nk ₁ . For example, in a CSI request for aperiodic feedback, these values can be dynamically changed. [109]

Cells can operate with a particular state transition pattern. It is assumed that this state may include sleep mode operation, and in some cases, it may not be desirable to perform the same higher layer measurement filtering on all resources. The WTRU may be configured with a pattern of subframes and/or subframes for which the WTRU may assume different cell states. In this case, the state/interference assumption can be for multiple frames. Moreover, once the state/interference hypothesis cycle is initiated, the WTRU can assume that the measurement has little to do with any measurements taken before that point. The WTRU may not assume that the cell must switch between only two states or that any of its neighbors switch between only two states. [110]

This pattern can be indicated for each appropriate cell in the broadcast information. Once configured to measure neighbor cells, the WTRU may provide an appropriate pattern from its serving cell. [111]

A WTRU may be configured with each of a plurality of sets of one or more CSI-IM and/or CSI procedures. At any given moment, one or more sets may be assumed for CSI feedback. The set can be configured via a higher layer (eg, RRC configuration). For example, the configuration may include a set index and a list of CSI-IM and/or CSI processes applicable to the set. The configuration may include a list of CSI-IM and/or CSI procedures, each having a list of indices indicating one or more sets to which each CSI-IM and/or CSI process belongs. Moreover, the WTRU may be reconfigured via a higher layer, such as a set of CSI-IM and/or CSI procedures, or a set of CSI-IM and/or CSI procedures to add or remove CSI-IM and/or CSI. process. The reconfiguration (eg, each reconfiguration) can replace the old collection with a new set of CSI-IM and/or CSI procedures. [112]

The cell may dynamically indicate to the WTRU which set of CSI-IM and/or CSI procedures it should assume for subsequent periodic or aperiodic feedback. For example, there may be a one-to-one mapping between the previous CSI process and the new CSI process. In this example, the new CSI process can reuse the periodic feedback configuration. The CSI process within the set can be configured with its own periodic feedback configuration (eg, reporting mode, periodicity, and reporting offset). The WTRU may return an indication that it has changed its set of CSI-IM and/or CSI procedures. To do so, the report type can be created (eg, confirmation of the switch of the CSI-IM and/or CSI process set). The report type may be sent by itself in the appropriate subframe, and the new set of CSI-IM and/or CSI procedures may only be applied to the type of report that appears on or after the subframe that transmitted the acknowledgement. . This confirmation can be reported along with the RI. This can be done by creating a combined report type. [113]

To dynamically indicate an appropriate set of CSI-IM and/or CSI procedures, the cell may use an information element in a previously existing DCI format, or may use a DCI format (eg, Format 5). The set of CSI-IM and/or CSI procedures may be configured to index, and, in the DCI format, the cell may include an index of a new set of CSI-IMs and/or CSI procedures to use. In another example, the WTRU may be configured with a bitmap of CSI-IM and/or CSI procedures, or a collection of CSI-IM and/or CSI procedures. In each of the appropriate DCIs, the bit map may indicate a set of related CSI-IM and/or CSI processes or CSI-IM and/or CSI processes. [114]

Each individual CSI-IM and/or CSI process can be dynamically added or removed by indicating the CSI-IM and/or CSI process index in the appropriate DCI. [115]

Each set of CSI-IM and/or CSI processes can be configured with a list of conditions or interferers. For example, set 1 can be configured with interferers or conditions A, B, and C, while set 2 can be configured with interferers or conditions B and D. The cell may indicate to the WTRU the condition or set of interferers that the WTRU may determine based on the condition or interferer received to determine which set of CSI-IM and/or CSI procedures it should use. A cell may indicate a condition or a collection of interferers (eg, an entire set) in a single dynamic configuration, thereby deleting any previously configured conditions or a collection of interferers. For example, in the first DCI, the cell may indicate the interferer or conditions A, B, and C. Therefore, the WTRU may use Set 1 in its subsequent CSI feedback report until further indication. Continuing with the example, in the second DCI, the cell may indicate the interferer or conditions B and D. Therefore, the WTRU may use Set 2 in its subsequent CSI feedback report until further indication. [116]

The set may be configured with a list of conditions or interferers, and the cells may use dynamic configuration instances to add or remove interferers or conditions. In the above example, after the first DCI for indicating the interferer or conditions A, B, and C, the WTRU may receive a second DCI indicating the addition of the interferer or condition D and removing the interferer or conditions A and C. After receiving this configuration, the WTRU may use Set 2 in its subsequent CSI feedback report until further indication. [117]

A code point may be present in the DCI to indicate to the WTRU that it may continue to use the same CSI-IM and/or post CSI process. However, it can be assumed that there is little relationship between any measurements made before this point and subsequent measurements. [118]

The dynamic indication of the set of CSI-IM and/or CSI procedures may again be used in CSI request bits in the previously existing DCI format. In this case, some code points may be configured to represent certain sets of CSI-IM and/or CSI procedures, while one code point may be used to indicate that the WTRU may continue the same CSI-IM and/or CSI process. However, it can be assumed that there is little relationship between any measurements taken before this point and subsequent measurements. [119]

Dynamic indications of the set of CSI-RS and/or CSI-IM and/or CSI processes can be pre-configured to be linked with dynamic configurable parameters. For example, a WTRU may be dynamically configured with a cell state. Moreover, the cell state can be pre-configured with a collection of CSI-IM, CSI-RS, and/or CSI processes. Once the cell state is configured, the set of CSI-IM, CSI-RS, and/or CSI processes may be implicitly indicated to the WTRU. [120]

The DCI may include a filtering mask that is used on one or more (eg, all) CSI-IM and/or CSI processes of subsequent CSI feedback. For example, the CSI process can be configured with a CSI-IM that appears in each fifth subframe. In this example, the WTRU may dynamically indicate that the CSI-IM present in the subframe that satisfies the modulo ( n _s , 10) = 0 should be used by the DCI for the subsequent feedback report. The dynamic indication may also include a filtering mask that is used for RSRP/RSRQ measurements of serving cells and/or neighbor cells. [121]

The subset of subframes can be configured for CSI measurement and reporting. A time division multiplex (TDD) WTRU may be configured with two types of downlink subframes. Some subframes can be considered to be always down chain and can be referred to as fixed downlink subframes. Other sub-frames, which may be referred to as flexible downlink frames, may be used for uplink transmission at some time and for downlink transmission at some time. [122]

The WTRU may feed back the CSI of the fixed or flexible subframe. The WTRU may feed back the CSI of the subframe in which the cell may be turned on or off. For example, a WTRU may be connected to a cell, and within a given subframe, the cell may be uplinked, downlinked, or closed. The WTRU may be able to make CSI measurements of cells in the off state. Once turned back on, this measurement may enable the eNB to schedule the WTRU (eg, immediately). The WTRU may be configured with a dynamic indication of the cell state (eg, on or off). The WTRU may be provided with a pattern of subframes in which the subframes may be treated as open, closed, fixed downlink, or flexible downlink. The WTRU may be configured to include measurements in at least one of a fixed downlink and/or a flexible downlink or a closed subframe in a periodic or aperiodic CSI feedback report. The WTRU may be configured with different CSI procedures for measurement, which may or may not include flexible downlink subframes and/or close subframes. The WTRU may be configured (e.g., dynamically) to include measurements made in the flexible downlink subframe and/or the closed subframe in the CSI feedback report. [123]

The WTRU may be configured with a CSI process, which may include fixed downlink, flexible downlink, and/or closed subframes. The CSI process may include CSI-IM and/or CSI-RS that may cover a fixed downlink, a flexible downlink, and/or a closed subframe. The CSI process may be configured with multiple CSI-RSs and/or CSI-IMs, each of which may override different combinations of subframe types. The WTRU may be configured with a set of CSI procedures, each with a different combination of CSI-IM or CSI-RS covering the subframe type. The WTRU may be configured with a set of blank patterns. When the WTRU performs a measurement of CSI feedback, the blank pattern can effectively remove certain subframes from consideration. For example, this can be provided as a restricted set of subframes or as a subframe piercing diagram. The blank pattern can be configured for one or many CSI processes, CSI-RS and/or CSI-IM. [124]

CSI-IM and/or CSI-RS configurations can be applied. The configuration may depend on the uplink or downlink configuration of the WTRU and may depend on the open or closed state of the serving cell used by the WTRU. The configuration can be managed to apply in certain (configured) subframe subsets that can be determined by the subframe type. For example, a set of available subframes may be explicitly provided to the WTRU in the configuration at the same time as the new uplink or downlink configuration or at the same time of the open or closed state and/or pattern. The set of available subframes may be determined from an open or closed configuration provided to the WTRU or a combination of TDD and the configuration. For example, a CSI-IM and/or CSI-RS configuration may imply that the CSI-IM and/or CSI-RS may be located on different types of subframes. The configuration may also include an indication of any restrictions on the suitability of CSI-IM and/or CSI-RS in certain types of subframes. For example, the CSI-IM located on each fifth subframe can appear in the flexible subframe. The configuration may include an indication that the WTRU knows that it will not be in the flexible subframe. The indication may include a list of closed subframes, fixed downlinks, and/or flexible downlinks to which the CSI-IM and/or CSI-RS may be applicable. [125]

The suitability of CSI-IM and/or CSI-RS and/or CSI procedures in different types of subframes can be configured, for example, by TDD configuration or reconfiguration of the uplink or downlink or reconfiguration of the open or closed state The instructions included in the configuration are dynamically configured. The suitability of CSI-IM and/or CSI-RS and/or CSI procedures in different types of subframes may be configured by an indication in the DCI. For example, the DCI that triggers the aperiodic CSI report may include an indication that informs the WTRU of the suitability of the CSI procedure and/or CSI-IM and/or CSI-RS for different types of subframes. This indication can be applied to current aperiodic feedback reports or to subsequent periodic and/or aperiodic feedback reports. The applicability of CSI-IM and/or CSI-RS and/or CSI procedures in different types of subframes may be used for resources with PDCCHs with aperiodic triggering (eg, it is a WTRU-specific search space or a common search space, It is configured in the PDCCH or in the EPDCCH, the EPDCCH resources used, and/or using the DCI format). The suitability of CSI-IM and/or CSI-RS and/or CSI procedures in different types of subframes may be one or more sub-messages of available subframe types and/or feedback reports included in CSI feedback requests. The explicit indication of the box number is configured. [126]

The indication may include a list of subframes in which CSI-IM and/or CSI-RS and/or CSI procedures may or may not be applicable. The indication may be provided by applicability of toggling on or toggling off measurements on different types of subframes (eg, fixed downlink, flexible downlink, and/or closed subframe) . [127]

A set of subframes to which CSI-IM and/or CSI-RS and/or CSI procedures are applicable may be semi-statically configured via higher layer messaging. For example, the RRC message is used to configure or reconfigure the uplink or downlink pattern in the WTRU, or to dial or disconnect cells, or to configure or reconfigure the on/off pattern, the RRC message may be included in An indication of the suitability of the measurements made on different types of sub-frames. [128]

The suitability of the CSI-IM and/or CSI-RS and/or CSI procedures on the subframe set may be implicitly determined by the type of subframe that receives the CSI request. For example, if the CSI request is received in a flexible downlink or closed subframe, measurements can be performed on the CSI-IM and/or CSI-RS and/or CSI procedures located in the flexible downlink or closed subframe. [129]

The suitability of the CSI-IM and/or CSI-RS and/or CSI procedures on the subframe set may be implicitly determined by the type of subframe including the CSI feedback report. [130]

The applicability of the CSI-IM and/or CSI-RS and/or CSI procedures on the set of subframes can be implicitly determined by the type of feedback. For example, whether the feedback is periodic or aperiodic can determine whether the measurement can be applied to a fixed downlink, a flexible downlink, and/or a closed subframe. [131]

The applicability of the CSI-IM and/or CSI-RS and/or CSI procedures on the subframe set may be implicitly determined by the WTRU's autonomous decision. For example, if the measurements in the flexible downlink or closed subframes are within the measurement threshold of the fixed downlink subframe, these measurements can be considered together for the feedback report. On the other hand, if the measurement in the flexible downlink or closed subframe is different from the fixed downlink subframe measurement by a threshold, the WTRU may autonomously decide to report both types of feedback. The WTRU may report a separate one of the two types of measurements according to a prioritization rule or based on measurements. [132]

In order to enable certain modulation commands (eg, high order modulation (HOM) such as 256-QAM), some eNBs may use power back shifting. Some eNBs may reduce their transmission power to limit errors due to physical limitations of the transmitter and/or receiver. The eNB may choose to use power back-off for the WTRU that is configured to receive the HOM. The eNB may use the HOM to post shift the power for transmission. The power back shift can be applied to a subset of the transmitted physical channels. For example, the eNB may post-dynamic power back for PDSCH transmission using HOM. The eNB may use full power for other channels and/or signals in the same subframe (eg, CRS, CSI-RS, (E) PDCCH, PCFICH, and/or PHICH). When channel estimation is performed on a non-backward shifted signal, the dynamic use of power back shifting can result in demodulation of the back shifted channel. The dynamic use of power back shift can affect the assumptions used for CSI calculations. The dynamic use of power back shifting can affect interfering cell measurements using dynamic power back shifting. [133]

The WTRU may be configured to power backshifting to be used at any given moment. This configuration may be performed by providing the WTRU with different values for P_A, P_B, and/or P_C for different subframes. For example, a first set of P_A, P_B, and/or P_C may be used for a subframe that uses power back shifting, while a second set of P_A, P_B, and/or P_C may be used for subframes that do not use power back shifting. This configuration can be done concurrently with possible HOM transmission configurations or can be configured independently. For example, the WTRU may be indicated if the subframe is using power back-shift. This indication can be provided dynamically (eg, on a per frame or per subframe basis). This indication can be provided using physical layer messaging to indicate the status of the subframe. This indication can be provided using different parameters (eg, RE mapping or sequence generator or OCC) for reference symbols located in different types of subframes. For example, when power back shifting is used, the CRS or CSI-RS can use the first sequence, and when the power back shift is not used, the CRS or CSI-RS can use the second sequence. The RE position of the CSI-IM may indicate whether power back shift is used. The indication of whether the subframe uses power backshifting may be provided using the presence of a certain type of signal (eg, CRS, CSI-RS, and/or CSI-IM). For example, the presence of a CSI-RS may indicate to the WTRU whether power back-off is being used. The indication of whether the subframe uses power back-off may be implicitly provided by reusing one or more values of the DCI used to assign the PDSCH transmission. For example, some MCS value or carrier indicator value, resource block assignment value, redundancy version, and/or precoded information value may be linked to transmissions with or without power back migration. [134]

The configuration using power back shifting can be provided semi-statically. For example, when power back-shifting is used, the WTRU may be provided with a set of subframes that may be provided to the WTRU when power back-shifting is not in use. [135]

The WTRU may be configured with a single hypothesis or multiple hypotheses to be used for CSI feedback in order to make appropriate assumptions about CSI calculations. The network can adjust the CSI according to its desired type of transmission. The WTRU may return CSI values for both transmission types. For example, a WTRU may have different back-shift report instances for each power back-off hypothesis. The WTRU may respond to the two power back-off hypotheses in the feedback report instance. The CSI process and/or CSI-RS and/or CSI-IM may be configured with a specific power back-off assumption. The configuration for the power back shift hypothesis for demodulation can be repeated for the power back shift hypothesis of the current feedback report. For aperiodic CSI reporting, what power backshift the WTRU uses can be explicitly indicated in the CSI request. For example, different CSI request values can be mapped to different power back-off assumptions. [136]

The use of power back-off for interference measurements may again use the examples disclosed herein for dynamic interference management to facilitate interference measurements. For example, a CSI process can be configured with multiple CSI-IMs, whereby different CSI-IMs can have different neighbor cell power back-off assumptions. The WTRU may be configured with different interference estimate averaging windows. The window can be linked to different power backshifts from neighboring cells. [137]

Measurements can be modified for a subset of resources. Neighbor cells with high levels of inter-cell interference can coordinate their resources to limit such interference. For example, each cell may be assigned a transmission beam and/or a set of subcarriers/PRBs/subbands and/or subframes, referred to herein as a subset of resources. Cells can be coordinated to optimize the selection of appropriate subsets of resources. For example, such coordination can be done via the X2 interface. In another example, a cell may sense the configuration of its neighbor cells and may independently select an appropriate subset of resources based on, for example, expected interference and cell traffic. In another example, the subset of resources of a cell may be implicitly determined from the PCI of the cell or the configured virtual cell ID (VCID). [138]

The subset of resources used by the small cells can be included in broadcast messages such as SIBs. In another solution, the serving cell may use higher layer messaging to configure the WTRU with resources available for downlink and/or uplink traffic. For example, the serving cell may communicate via a higher layer to indicate a subset of subbands available for downlink operation. In another example, the WTRU may be configured with a bit map parameter that is linked to a set of possible resources. For example, if a cell uses a PRB subset, such a bitmap parameter can be a PRB subset limit ( PRBSubsetRestriction ). Using dynamic indications (eg, via DCI), the cell may use the bit map parameters to dynamically configure the WTRU with a suitable subset, where '1' may indicate that the sub-resource is available, and '0' may indicate that Sub-resources are not available. In another aspect, the WTRU may be configured with a limited list of n possible subsets of resources via higher layers. In DCI, cells can be used A bit to indicate the appropriate subset of resources. [139]

The cell may configure the WTRU with a subset of resources that may be considered simultaneously. In one such example, each CSI-IM and/or CSI process can be configured with a suitable subset of resources. In another example, each subset of resources may be configured with its own set of CSI-IM and/or CSI processes. In another example, some or all of the CSI-IM and/or CSI processes may be applicable to multiple subsets of resources. [140]

Another example may involve reporting a feedback with a subset of resources. For example, when a WTRU is configured with a subset of resources, the WTRU may perform its measurements only on a suitable subset of resources, regardless of higher layer measurements and/or CSI for, for example, RSRP/RSRQ. Moreover, when calculating the feedback report, the WTRU may assume that the subset of resources may be taken as the entire bandwidth. For example, a WTRU may be configured with the first 20 PRBs of a carrier. In such a configuration, the WTRU may assume that for feedback reporting, the broadband measurement may only be applied to the first 20 PRBs. The WTRU may also be configured as a sub-band of a subset of 20 PRBs. In such an example, the RI and wideband CQI/PMI can be measured only on the configured 20 PRBs and not over the entire carrier bandwidth. This also applies to RSRP/RSRQ measurements. [141]

If the WTRU is configured with multiple resource subsets, the WTRU may be able to perform measurements on a combination of subsets. For example, the WTRU may be able to report a wide frequency RI that assumes a combination of multiple subsets, each subset including n PRBs. [142]

A WTRU may be configured with multiple subsets of resources, such as multiple sub-band subsets. A subset of resources does not need to include adjacent resources. A subset of resources can have its own feedback mode associated with it. The WTRU may report feedback values (eg, values of RI, CQI, and/or PMI) for each subset of resources. The subset of resources may have, for example, a wideband feedback report including a subset of the entire resource, and a subband report such as a subset of the subset of resources. The WTRU may also be configured to feed back reports for resource subset combinations. For example, a WTRU may be configured to include a first subset of resources of PRBs 0, 1, 2, and 4 and a second subset of resources including PRBs 3, 5, 6, and 7. The WTRU may feed back independent RI values for the two subsets and RI values for the combination of the two subsets. The WTRU may be configured to correlate reports of two subsets of resources. For example, the RI value reported for the first subset of resources may depend on the RI value reported for the second subset of resources. [143]

A WTRU configured with multiple subsets of resources may indicate to the eNB its preferred or least preferred subset of resources. This indication can be explicitly provided by rewarding the pre-configured index. Some report instances can be configured for a preferred subset of resources. The report instance may not always be for the same subset. The WTRU may provide an indication of a suitable subset of resources. The WTRU may select a set of subsets of resources that may provide feedback for the set of subsets of resources. In the set of resource subsets of the selected WTRU, the WTRU may include a bitmap of the subset of resources for which the feedback report is directed. [144]

A dynamic indication of a subset of resources may trigger the WTRU to modify its measurements. For periodic measurements, it may not be feasible or possible for the WTRU to modify its measurements for the next reporting instance. Thus, the change in the subset of resources obtained in subframe n can be applied to all subsequent periodic feedback reports in subframe n+k , where k can be hard coded or can be configured via higher layer messaging. Similarly, the complexity of aperiodic reporting may increase. Thus, for aperiodic requests that may include changes in the subset of resources and may be included in subframe n , the WTRU may be expected to provide CSI feedback in subframe n+k , where k may be greater than 4 and may be hard coded Or it can be pre-configured via a higher layer. [145]

Moreover, the subset of resources included in the aperiodic trigger can be uniquely applied to one aperiodic feedback report or can be applied to all subsequent aperiodic feedback reports and/or periodic feedback reports. The subset of resources included in the DCI independent of the aperiodic trigger can be applied to all subsequent periodic and/or aperiodic feedback reports. [146]

Feedback reports can be used to enable or facilitate down-chain power control. It is beneficial to use adaptive power control for small cells. Each small cell can adaptively determine the appropriate downlink power value for each transmitted message. The appropriate downlink power value may be a function of the signal strength requirement of the WTRU served by the small cell, and possible interference effects on the WTRU not served by the small cell. [147]

The WTRU may feed back the allowed interference values of the set of neighbors, which may be pre-configured. This can enable or facilitate adaptive downlink power control. For example, a WTRU may feed back to its serving cell an SINR value that may have a cell identifier that is available for multiple neighbor cells. The WTRU may return a set of neighboring cells from which the WTRU may receive an interference level greater than a threshold. This threshold may be pre-configured at the WTRU or may be determined to be a value that may negatively impact the WTRU's reception capabilities. [148]

The WTRU may include additional information when it returns a set of neighbor cells that it may cause substantial interference. For example, this additional information may include an index for each interfering cell. This additional information may include interference that currently affects the WTRU. This interference may include CQI terms, SINR terms, and/or absolute interference values that are reinterpreted by the eNB for indicating the signal quality of the interference. Additional information included by the WTRU may include the best and/or worst partner RI, CQI, and/or PMI. This may indicate a transmission parameter that the interfering neighbor cell may use to minimize interference to the WTRU. As another example, this may indicate the transmission parameters that are the most disruptive to the WTRU. The additional information included by the WTRU may include a path loss value for each interfering cell. The path loss value can be determined if the WTRU is provided with a list of transmission powers for each cell. Assuming that cells can use adaptive downlink power control, it may be necessary to regularly update the WTRU with the adjacent transmit power of each cell. Cells can use fixed power on some channels and/or reference signals. This may allow the WTRU to better determine the path loss to each cell. Additional information included by the WTRU may include values indicative of received interference power, RSRP, and/or SINR for each neighbor cell. [149]

Once fed back to the RI, QCI, and/or PMI for the serving cell, the WTRU may respond to any of these interference parameters. There may be a correlation between the interference parameter and the desired serving cell transmission parameter. For example, a WTRU may indicate a desired PMI for its serving cell and may couple the report with an undesired PMI value for a neighbor cell. The WTRU may return multiple values in the RI, CQI, and/or PMI. Each set of feedback values may depend on a particular interference measure from one or more neighbor cells. [150]

In a dynamic load transfer scheme, a WTRU may be forced to connect to a cell that does not correspond to its optimal cell. In such a scenario, when the WTRU notices that its RSRP is greater than the cell of its current serving cell, it may not be desirable for the WTRU to trigger a measurement report, assuming this will be in each reporting instance. To limit such triggering, the WTRU may be configured to measure the offset. [151]

For example, a WTRU may be configured with a positive deviation of its serving cell. This may limit the likelihood that the WTRU may determine that the neighbor cell has a higher RSRP, and thus may force the WTRU to assume that its current serving cell is optimal. In another example, the WTRU may be configured with a negative offset for its neighbor cells. This may limit the likelihood that the WTRU may find a higher RSRP neighbor cell than its current serving cell. [152]

Due to dynamic changes in the WTRU's distribution, this bias can be dynamically changed to improve or optimize network operation. In such a scenario, the WTRU may be semi-statically or dynamically indicating the cell deviation of its serving cell and any applicable neighbor cells. The WTRU may be configured with a list of deviations when the network triggers a measurement report. In another example, the WTRU may be configured via higher layer messaging for a later measurement and a semi-static set of deviations that the WTRU triggers reporting. [153]

A new set of deviations can be dynamically indicated to each WTRU via the DCI. The deviations may all be new numbers or may be cumulative functions used with pre-compensation deviations. The DCI format using the RNTI set can be configured. Some or all of the serving cells may be configured to monitor the DCI format using the appropriate one or more RNTIs. Each RNTI may indicate a particular cell on which the new bias (or delta delta value) included in the DCI is applied. [154]

The WTRU may be dynamically indicating whether the neighbor cell is active or dormant, or is in any other state. Depending on the state of the neighbor cell, the WTRU may use different pre-matching deviations for the measurement. The set of deviations available for all states of neighbor cells can be dynamically updated. [155]

The WTRU may be triggered to report measurements of the set of cells. For example, whenever a WTRU is triggered for a measurement report, the WTRU may report a measurement of its x best cells (eg, where x may be 3). For example, a measurement report can be triggered when a change in a member of the set of x best cells occurs. [156]

For a cell included in the set of x best cells, the cell may be part of a pre-matched cluster. For example, cells A, B, and C can be the three best cells of the WTRU. If the fourth cell, such as cell D, becomes offset more than any of the three cells (eg, C), the WTRU may report the cell as long as D is also part of the pre-configured cluster. Measurement of elements A, B and D. [157]

The cells can provide an indication of the traffic load to each other. For example, the indication can be provided via the X2 interface. For example, the first cell may indicate to the second cell that it may or may not be able to accommodate more WTRUs. A cell may indicate to its neighbor cells the total number of WTRUs connected to that cell. The cell may indicate to its neighbor cell the number of WTRUs with active file downloads or uploads.

Although features and elements are described above in a particular combination, it will be understood by those of ordinary skill in the art that each feature or element can be used alone or in combination with any of the other features and elements. Moreover, the methods described herein can be implemented in a computer program, software or firmware, which can be embodied in a computer readable medium executed by a computer or processor. Examples of computer readable media include electronic signals (transmitted via a wired or wireless connection) and computer readable storage media. Examples of computer readable storage media include, but are not limited to, read only memory (ROM), random access memory (RAM), scratchpad, cache memory, semiconductor memory device, magnetic media (eg, internal hard drive) And removable disks), magneto-optical media, and optical media (for example, compact discs (CDs) or digital versatile discs (DVDs)). A processor associated with the software can be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

100‧‧‧Communication system
102, 102a, 102b, 102c, 102d‧ ‧ ‧ wireless transmit / receive unit (WTRU)
103/104/105‧‧‧Radio Access Network (RAN)
106/107/109‧‧‧ core network
108‧‧‧Public Switched Telephone Network (PSTN)
110‧‧‧Internet
112‧‧‧Other networks
114a, 114b, 180a, 180b, 180c‧‧‧ base station
115/116/117‧‧‧Intermediate mediation
118‧‧‧Processor
120‧‧‧ transceiver
122‧‧‧Transmission/receiving components
124‧‧‧Speaker/Microphone
126‧‧‧ keyboard
128‧‧‧Display/Touchpad
130‧‧‧ Non-removable memory
132‧‧‧Removable memory
134‧‧‧Power supply
136‧‧‧Global Positioning System (GPS) chipset
138‧‧‧ peripheral devices
140a, 140b, 140c‧‧‧ Node B
142a, 142b‧‧‧ Radio Network Controller (RNC)
144‧‧‧Media Gateway (MGW)
146‧‧‧Mobile Exchange Center (MSC)
148‧‧‧Serving GPRS Support Node (SGSN)
150‧‧‧Gateway GPRS Support Node (GGSN)
160a, 160b, 160c‧‧‧e Node B
162‧‧‧Mobility Management Entity (MME)
164‧‧‧ service gateway
166‧‧‧ Packet Data Network (PDN) Gateway
182‧‧‧Access Service Network (ASN) Gateway
184‧‧‧Action IP Local Agent (MIP-HA)
186‧‧‧Authentication, Authorization, Accounting (AAA) Server
188‧‧ ‧ gateway
Iub, IuCS, iur, S1, X2‧‧ interface
R1, R3, R6, R8‧‧‧ reference points

[05]

Understood from the following more detailed description in conjunction with the accompanying drawings given by way of example obtained, wherein: [06] FIG. 1A is a first embodiment in which one or more system diagram of an example of the communication system according to an embodiment of the disclosure; [ 07] FIG. 1B is a system diagram of an exemplary wireless transmission/reception unit (WTRU) that can be used in the communication system shown in FIG. 1A; [08] FIG. 1C is a communication system that can be shown in FIG. 1A. System diagram of an example radio access network and an example core network used; [09] Figure 1D is another example radio access network and another example core that can be used in the communication system shown in Figure 1A System diagram of the network; [10] Figure 1E is a system diagram of another example radio access network and another example core network that can be used in the communication system shown in Figure 1A; and Figure 2 is A diagram showing an example of an allowable pattern of state transitions in cells in a wireless network.

Claims (24)

A method for operating a wireless network comprising a plurality of cells, the method comprising: defining a time period during which a cell can perform a state transition; communicating the defined time period to a A WTRU; and configuring a channel state information (CSI) resource for the WTRU to perform a measurement and report a CSI measurement for a cell state hypothesis. The method of claim 1, wherein the cell state hypothesis comprises at least one of a fixed downlink frame state, a flexible downlink subframe state, and a closed subframe state. The method of claim 1, wherein the WTRU is configured to report a measured one of at least one of a fixed downlink subframe, a flexible downlink subframe, and a closed subframe. The Channel State Information (CSI) measurement results include configuring a CSI procedure for the WTRU based on the cell state hypothesis. The method of claim 1, wherein configuring the WTRU to report a CSI measurement for a cell state hypothesis comprises applying at least one of a CSI process, a CSI-IM configuration, and a CSI-RS configuration By. The method of claim 4, wherein the at least one of a CSI process, a CSI-IM configuration, and a CSI-RS configuration is applicable to at least one of a subset of time resources and a subset of frequency resources. One. The method of claim 1, wherein configuring the WTRU to report a CSI measurement for a cell state hypothesis comprises configuring a period for the WTRU, the interference being assumed to be fixed on the cycle. The method of claim 1, further comprising indicating whether power back shifting is used in a subframe. The method of claim 7, wherein indicating whether power backshifting is used in a subframe includes providing a dynamic indication of power back shifting. The method of claim 8, wherein providing a dynamic indication of power back shifting comprises providing at least one of the following to indicate whether power back shifting is used in a subframe: physical layer communication, a reference symbol A parameter, a cell specific reference symbol (CRS), a CSI-RS, a CSI-IM, and a Downlink Control Information (DCI) value. The method of claim 1, further comprising configuring a set of resources for the WTRU to perform an interference measurement on the set of resources. The method of claim 10, further comprising reporting the interference measurement to a serving cell. The method of claim 10, further comprising calculating an RRM measurement based on the interference measurement. A device comprising: a processor; and a memory comprising a plurality of instructions, when the plurality of instructions are executed by the processor, causing the device to: define a time period during which a cell The element can perform a state transition; communicate the defined time period to a WTRU; and configure a channel state information (CSI) resource for the WTRU to perform a measurement for a cell state hypothesis and Report a CSI measurement. The device of claim 13, wherein the cell state hypothesis comprises at least one of a fixed downlink frame state, a flexible downlink subframe state, and a closed subframe state. The apparatus of claim 13, wherein the memory includes an additional instruction for configuring the WTRU to report a fixed by configuring a CSI procedure for the WTRU according to a cell state hypothesis. A measured channel state information (CSI) measurement result performed in at least one of a downlink subframe, a flexible downlink subframe, and a closed subframe. The apparatus of claim 13, wherein configuring the WTRU to report a CSI measurement for a cell state hypothesis comprises applying at least one of a CSI process, a CSI-IM configuration, and a CSI-RS configuration One. The apparatus of claim 16, wherein at least one of a CSI process, a CSI-IM configuration, and a CSI-RS configuration is applicable to at least one of a subset of time resources and a subset of frequency resources. One. The apparatus of claim 13, wherein configuring the WTRU to report a CSI measurement for a cell state hypothesis comprises configuring a period for the WTRU, on which the interference is assumed to be fixed. The device of claim 13, wherein the memory comprises an additional command for indicating whether power backshifting is used in the subframe. The device of claim 19, wherein the memory includes an additional instruction for indicating whether power back shifting in a subframe is at least by providing a dynamic indication of power back shifting used. The device of claim 20, wherein the memory comprises additional instructions for indicating whether power backshifting is used in at least one subframe by at least providing at least one of the following: To provide a dynamic indication of power back-shift: physical layer communication, a parameter of a reference symbol, a cell specific reference symbol (CRS), a CSI-RS, a CSI-IM, and a downlink control information (DCI) value. The apparatus of claim 13 wherein the memory comprises additional instructions for configuring a set of resources for the WTRU to perform an interference measurement on the set of resources. The device of claim 22, wherein the memory comprises an additional instruction for reporting the interference measurement to a serving cell. The device of claim 22, wherein the memory comprises additional instructions for calculating an RRM measurement based on the interference measurement.