Abstract: A method and apparatus for neighbor discovery in a wireless communication system are disclosed. A neighbor seeking wireless transmit/receive unit (WTRU) may send a first beacon based on configuration information provided by the network. The neighbor WTRUs receive the first beacon and may send either a report to the network or send a second beacon to the neighbor seeking WTRU. The network may then provide neighbor WTRU information to the neighbor seeking WTRU. The neighbor discovery may be performed within a pre-defined group of WTRUs that is formed based on proximity to the WTRU and/or an attribute of the WTRU. The neighbor discovery procedure may be performed to find neighbor WTRUs in case where a WTRU fails to find any network. A neighbor list may be generated by the neighbor seeking WTRU by measuring reference signals transmitted by neighbor WTRUs on an uplink to the network.

Abstract: A method and apparatus for establishing peer-to-peer communication in a wireless network is described. A wireless transmit/receive unit (WTRU) may receive configuration information comprising periodic resources comprising time and subcarrier resources from a base station of a wireless network. The time and subcarrier resources may be used in discovery of other WTRUs. The WTRU is further configured to transmit an identification in the allocated resources and to transmit a synchronization signal to a peer WTRU for timing synchronization of the peer WTRU.

Abstract: A method and apparatus for offloading backhaul traffic are disclosed. A first base station may detect a condition triggering backhaul traffic offloading for a wireless transmit/receive unit (WTRU). The first base station may establish a wireless connection with a second base station, and offload at least one bearer of the WTRU onto the second base station via the wireless connection. The first base station may be a macro-cell base station and the second base station may be a femto-cell base station having a wired connection to Internet and a mobile operator core network. The first or second base station may include a relay functionality and act as a relay between the WTRU and the other base station. The backhaul link may be established using a Uu, Un, X2 interface or any other interface over a licensed or license-exempt frequency, a TV white space frequency, etc.

Abstract: Methods and apparatus for millimeter wave (mmW) beam acquisition are disclosed. An apparatus includes a transmitter configured to transmit millimeter wave (mmW) WTRU (mmW WTRU) information over a cellular system to a base station a receiver and a processor. The receiver receives a list of candidate mmW base stations (mB) including mmW acquisition start timing information from the base station, and the processor calculates correlation values around the received mmW acquisition start timing information for the mBs in the list.

Abstract: A method and apparatus for advanced topology (AT) policy management for direct communication between wireless transmit/receive units (WTRUs) is described. A WTRU configured to communicate directly with at least one other WTRU in an AT mode of operation includes a memory, a central processing unit and an AT policy unit that is separate from the CPU. The AT policy unit is configured to store at least one AT policy in the memory, activate and de-activate an AT application that runs the AT mode of operation based on the at least one AT policy stored in the memory, receive data from at least one application within the WTRU other than the AT application, and control the at least one application within the WTRU other than the AT application based on the at least one AT policy stored in the memory.

Abstract: A method and apparatus for cross link (XL) establishment are disclosed. In the method and apparatus, a XL between a terminal wireless transmit/receive unit (T-WTRU) and a helper WTRU (H-WTRU) is established. The T-WTRU and the H-WTRU may be configured to operate in a plurality of RRC states and a plurality of RRC substates. To establish the XL, neighbor discovery, association information exchange, and a H-WTRU selection may be performed. Radio resource control (RRC) configuration of the T-WTRU and the H-WTRU may also be performed. In the method and apparatus, coverage for a T-WTRU may be handed over between a network and a H-WTRU or between two H-WTRUs.

Abstract: A method and apparatus for establishing peer-to-peer communication and performing forwarding under the control of a cellular network are described. A seeking wireless transmit/receive unit (WTRU) may receive a timing signal from at least one discoverable WTRU controlled by a base station. The seeking WTRU may estimate the quality of a radio link (i.e., path loss) between the seeking WTRU and the discoverable WTRU, and determine, (e.g., based on a threshold established by the base station), whether or not to report the estimated radio link quality to a base station that controls the discoverable WTRU. The power of the timing signal may be ramped up in predetermined steps such that the transmission power at any given time is known and may be used by the seeking WTRU for estimating the radio link quality. The timing signal may include at least one of a primary preamble or a secondary preamble.

Abstract: A method, apparatus and system for wireless communication are described. The method includes transmitting and receiving data to and from one or more wireless transmit/receive units (WTRUs) via an underlay system access link. The underlay system is non-standalone, and control information is provided from an overlay system. An underlay base station is linked to other underlay base stations to implement a mesh backhaul. The method also includes transmitting and receiving at least a portion of the data to or from an overlay base station via backhaul links and receiving control data from the overlay base station. The data is split at a packet data convergence protocol (PDCP) entity, and the PDCP entity terminates in the overlay base station and a radio link control (RLC) entity terminates in the underlay base station.

Abstract: A method and apparatus for controlling crosslink (XL) establishment are disclosed. In the method and apparatus, the XL between a terminal wireless transmit/receive unit (T-WTRU) and a helper WTRU (H-WTRU) is controlled, whereby the T-WTRU and the H-WTRU may be in a radio resource control (RRC) Idle mode and may perform discontinuous reception (DRX). Further, the T-WTRU may transition between infrastructure coverage mode and WTRU-to-WTRU (W2W) coverage mode. Additionally, neighbor discovery and H-WTRU selection are performed and association between the T-WTRU and H-WTRU is established and maintained.

Abstract: Data traffic may be mapped such that it may be routed via a component carrier. The data traffic may be mapped based on QoS, traffic offload, or the like. This may provide the ability to map certain data to specific component carriers. For example, this may provide a user subscription model with the ability to map one or more services to license exempt (LE) carriers, but not to other carriers. As another example, a user downloading a high definition movie may not want this to be counted towards his or her monthly quota on a licensed carriers or may want to pay flat rate to access supplementary carriers for such services. Allowing data to be mapped such that it may be routed via a component carrier via a component carrier may allow the user to map the data for the high definition movie to a LE carrier.

Abstract: Disclosed herein is HARQ management, scheduling, and measurements, among other things, for cooperative communication. For example, methods herein may be used in situations wherein relaying or helping mechanisms may comprise the use of a relay node which is part of a fixed infrastructure or a relay node which may be a mobile wireless transmit/receive unit (WTRU). In said situations, a first transmission with first data is established between an evolved NodeB (eNB) and a WTRU. A second transmission with second data is established between a relay node (RN) and the WTRU. Said first and second data are combined for decoding. A single HARQ feedback for said first and second transmissions is sent from the WTRU to the eNB.

Abstract: Disclosed herein are measurement and interference avoidance for direct device-to-device (D2D) links. A method may be implemented by a wireless transmit/receive unit (WTRU). The method may include determining a sounding reference signal (SRS) to detect high interference and facilitate measurements on a link with another WTRU. The method may also include using the SRS on a direct link with another WTRU.

Abstract: A method and apparatus for mobility for device-to-device (D2D) communications is disclosed. A WTRU may store a proximity detection configuration that includes a measurement object corresponding to at least one discovery signal property, perform a proximity detection measurement to detect a discovery signal property, and then establish D2D communication. A radio resource control (RRC) Measurement Report may be received from a WTRU. Methods for D2D mobility procedures are also disclosed including mobility to or from a direct path, to or from a local path, to or from an infrastructure path, changing serving cell, and cell reselection. Other embodiments include: behavior upon mobility failure, radio link failure, and direct link failure. Security configuration and activation methods and apparatuses are also disclosed. Network methods for inter-eNB management are also disclosed.

Abstract: A method and apparatus are described for supporting a two-stage device-to-device (D2D) discovery using a D2D interworking function (IWF). A D2D IWF component may be configured to perform mapping between an application running on an application server and a third generation partnership project (3GPP) network, and provide a set of application programming interfaces (APIs) to allow discovery to be provided as a service to D2D applications. An application identifier may be mapped to a 3GPP identifier. Further, a method and apparatus are described for performing client-server discovery. A first wireless transmit/receive unit (WTRU) may be configured for a listen-only operation, and a second WTRU may be configured to transmit beacons. The first and second WTRUs may perform a radio access network (RAN) discovery procedure at an access stratum (AS) layer. A method and apparatus for performing charging for D2D service using a D2D IWF are also described.

Abstract: A method and apparatus are described for maintaining communications over a bearer when at least one of two wireless transmit/receive units (WTRUs) transition to idle mode. In one case, a direct WTRU-to-WTRU bearer may be released in response to a first one of the WTRUs transitioning to idle mode. A second one of the WTRUs may send a first of a plurality of packets to the first WTRU via a default packet data network (PDN) connection or a default bearer towards the PDN connection. The first packet may have a destination Internet protocol (IP) address of the second WTRU and trigger paging to the first WTRU. The first WTRU may transition to connected mode in response to the paging. Other cases may release a portion of a bearer, rather than the entire bearer. A method and apparatus for initiating proximity service bearer establishment is also described.

Abstract: A wireless communication network and method are described for enhancing cell-edge performance of a wireless transmit/receive unit (WTRU). The WTRU may establish a connection with a plurality of sites via respective downlinks (DLs). Each DL may include at least one DL component carrier (CC) that operates on a frequency that is the same or different than one or more of the other CCs. The sites may manipulate their transmit power for a particular CC operating frequency such that the distance from a particular one of the sites to its cell boundary may become larger by increasing its transmit power on the particular frequency, and the distance from at least one of the other sites to its respective cell boundary may become smaller by decreasing its transmit power on the particular frequency. Thus, a coverage overlap between different CC frequencies may be created while maintaining a frequency reuse pattern of one.

Abstract: A method and apparatus for establishing peer-to-peer communication and performing forwarding under the control of a cellular network are described. A seeking wireless transmit/receive unit (WTRU) may receive a timing signal from at least one discoverable WTRU controlled by a base station. The seeking WTRU may estimate the quality of a radio link (i.e., path loss) between the seeking WTRU and the discoverable WTRU, and determine, (e.g., based on a threshold established by the base station), whether or not to report the estimated radio link quality to a base station that controls the discoverable WTRU. The power of the timing signal may be ramped up in predetermined steps such that the transmission power at any given time is known and may be used by the seeking WTRU for estimating the radio link quality. The timing signal may include at least one of a primary preamble or a secondary preamble.

Abstract: A method and apparatus for reliably transmitting data by transmitting a plurality of radio link control (RLC) unacknowledged mode (UM) protocol data units (PDUs) over at least one primary channel and at least one auxiliary channel. If at least one RLC UM PDU is missing from the data transmitted over the primary channel, the missing RLC UM PDU is obtained from the auxiliary channel after a predetermined delay. A service data unit (SDU) is completed by combining PDUs received over the primary channel with at least one missing PDU received over the auxiliary channel. The SDU is sent to an application layer. If the missing PDU cannot be obtained before a predetermined time period expires, the transmitted data is deleted. The RLC UM PDUs may be used for streaming multicast applications.

Abstract: A method and apparatus for combined medium access control (MAC) and radio link control (RLC) processing are disclosed. For uplink processing, a combined MAC/RLC (CMR) entity generates an SDU descriptor and allocates protocol data unit (PDU) descriptor resources. A protocol engine (PE) populates a PDU descriptor for each PDU carrying at least a portion of the SDU and generates a MAC PDU in a physical layer shared memory based on the SDU descriptor and the PDU descriptor. The MAC PDU is generated while moving RLC SDU data from the bulk memory to the physical layer shared memory. For downlink processing, received MAC PDUs are stored in the physical layer shared memory. The PE reads MAC and RLC headers in the MAC PDU and populates an SDU segment descriptor (SD) and corresponding PDU descriptors for each SDU segment. The CMR entity merges SDU SDs that comprise a same RLC SDU.