BR112017019167B1 - METHOD AND APPARATUS FOR FEEDBACK OPERATIONS IN MMWAVE NETWORKS AND COMPUTER READABLE MEMORY - Google Patents

Abstract

Method, systems and apparatus are described for discovery operations in a millimeter wave wireless communication system. A first base station of the millimeter wave wireless communication system may determine a timing parameter and a propagation parameter associated with a second base station of the millimeter wave wireless communication system. The first base station may perform a discovery procedure with the second base station based at least in part on the timing parameter and propagation parameter. At least a portion of the discovery procedure may be performed wirelessly via the millimeter wave wireless communication system. The first base station may establish a return communication link with the second base station based on the discovery procedure.

Description

REFERENCES

[0001] The present patent application claims priority to US patent application number 14/842,679 of Islam et al., entitled “Methods for backhaul operations in Millimeter wave networks,” filed; and US provisional patent application number 62/131,787 to Islam et al. entitled “Methods for backhaul operations in millimeter wave networks,” filed March 11, 2015; each of which is assigned to the assignee hereof.

BACKGROUND

[0002] The present disclosure, for example, relates to wireless communication systems and more particularly to return operations in a millimeter wave wireless communication system.

DESCRIPTION OF RELATED TECHNIQUE

[0003] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, message sending, broadcast, and so on. These systems may be multiple access systems capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and energy). Examples of such multiple access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and frequency division multiple access (FDMA) systems. orthogonal frequency division (OFDMA).

[0004] As an example, a wireless multiple access communications system may include multiple base stations, each simultaneously supporting communication for multiple communications devices, otherwise known as user equipment (UE). A base station can communicate with UEs on downlink channels (e.g., for transmissions from a base station to a UE) and uplink channels (e.g., for transmissions from a UE to a base station). A base station can communicate, directly or indirectly, with other base stations through return links.

[0005] A base station, in a conventional communications system, typically enjoys a robust link with a network entity that coordinates aspects of discovery and return communications, e.g., the network entity provides timing information, cell identity , etc., to neighboring base stations to coordinate discovery and return transmissions. Base stations operating in the millimeter wave (mmW) frequency bands, e.g., 28 GHz, 40 GHz, 60 GHz, etc., may be associated with a reduced coverage area (e.g., a smaller geographic footprint, directional transmissions only , etc.) which may result in deploying a much larger number of base stations to provide acceptable coverage areas. Such large-scale mmW base station deployments can impact the quality and availability of links to a network entity. For example, some mmW base stations may be deployed in areas with limited bandwidth links to a network entity and, in some examples, no links to a network entity. In a conventional cellular communications system, base stations may rely on a wired connection to a network entity and therefore cannot typically perform discovery over wireless media. Such mmW base stations with limited or no links to a network entity will need to be able to discover other mmW base stations to perform callback operations. Furthermore, such wireless overlay operations can provide a more beneficial deployment scheme for a dense population of mmW base stations, e.g., providing a lower cost and more feasible option for installing fiber optic communication lines to each mmW base station.

SUMMARY

[0006] The described features refer in general to one or more improved systems, methods and/or apparatus for return operations in a mmW wireless communication system. Certain aspects of the present disclosure employ various approaches for a mmW base station to determine certain parameters associated with another mmW base station to perform a discovery procedure. For example, a first mmW base station may access, identify, or otherwise determine parameters for a second mmW base station associated with timing, propagation, and the like, e.g., a first set of communication parameters for the second base station. of mmW. The first set of communication parameters may include a sufficient amount of information associated with the second mmW base station to allow the first mmW base station to initiate a discovery procedure with the second base station. The discovery procedure, or at least a portion thereof, may be performed via the mmW wireless communication system.

[0007] In certain aspects, the first mmW base station may determine the first set of communication parameters using a blind detection mode, using a network-aided mode, using a UE-aided mode, or combinations thereof. An example of a blind detection mode may include the first base station refraining from transmitting a synchronization signal during a synchronization period and instead listening for a synchronization signal from the second base station. A synchronization signal detected from the second base station may provide sufficient information for the second base station to allow the first base station to initiate the discovery procedure. An example of a network-aided mode may include the first base station using a limited link (e.g., low bandwidth link, limited data link, etc.) with a network entity to determine the first set of network parameters. communication. An example of a UE-aided mode may include identifying a UE that is in communication with the first base station and the second base station. The first base station may leverage the UE to exchange information with the second base station to determine the first set of communication parameters. In general, during the discovery procedure, the first base station may identify or determine additional communication parameters associated with the second base station, e.g., a second set of communication parameters. Examples of the second set of communication parameters may include coding and modulation schemes (MCS), frame alignment timing information, beacon transmission timing information, etc.

[0008] In a first illustrative set of examples, a method for wireless communication in a millimeter wave wireless communication system is described. The method may include determining, by a first base station of the millimeter wave wireless communication system, a timing parameter and a propagation parameter associated with a second base station of the millimeter wave wireless communication system; and performing a discovery procedure with the second base station based at least in part on the timing parameter and propagation parameter, wherein at least a portion of the discovery procedure is performed wirelessly via the millimeter wave wireless communication system.

[0009] In some examples, the method may include: identifying a network entity having a connection to the first base station and the second base station; and receiving information from the network entity indicative of at least one of the timing parameter, or propagation parameter, or a combination thereof. The method may include transmitting information to the network entity indicating a request to establish a return communication link with the second Base station. The network entity may be connected to the first base station and the second base station via a wired communication link. The network entity may be connected to the first base station and the second base station via a wireless communication link associated with a third base station of the millimeter wave wireless communication system.

[00010] In some examples, information received from the network entity indicative of at least one of the timing parameter or the propagation parameter may be based at least in part on a previous return communication link from the first base station or second base station, or a geographic location of the first base station and second base station, or a message received from one or more user equipment (UEs) associated with communications through the first base station or second base station or combinations thereof . The information received from the network entity may include an indication of a timing window parameter associated with a timing window for attempting to perform the discovery procedure, a search beam parameter associated with a number of beams being transmitted by the second base station, a sequence parameter associated with a transmission sequence of the second base station or combinations thereof, a base station capabilities parameter identifying one or more capabilities of the second base station, or combinations thereof.

[00011] In some examples, the method may include: refraining, by the first base station, from transmitting a synchronization signal during a synchronization period; and monitoring, by the first base station during the synchronization period, relative to a synchronization signal transmitted by the second base station. The method may include, after determining that the second base station has transmitted the synchronization signal, initiating the discovery procedure based at least in part on the transmitted synchronization signal. The message for the second base station to initiate the discovery procedure may be sent over a directional random access channel (DRACH).

[00012] In some examples, the method may include determining, by the first base station, a predetermined periodicity associated with refraining from transmitting the synchronization signal and monitoring for transmission of the synchronization signal from the second base station. The predetermined frequency may be determined based at least in part on information received from a network entity. The synchronization signal transmitted from the second base station may include a directional primary synchronization signal (DPSS).

[00013] In some examples, the method may include determining, by the first base station, that at least one user equipment (UE) is in communication with the first base station and the second base station; and relaying one or more messages to the second base station through the at least one UE to determine at least one of the timing parameter or propagation parameter associated with the second base station. The method may include: receiving one or more messages from the UE including information associated with the second base station; and determining execution of the discovery procedure based at least in part on one or more messages received from the UE.

[00014] In some examples, information received from the UE associated with the second base station may include an indication of a timing window parameter associated with a timing window for attempting to perform the discovery procedure, a search beam parameter associated with a number of beams being transmitted by the second base station, a sequence parameter associated with a transmission sequence of the second base station, a base station capabilities parameter identifying one or more capabilities of the second base station, or combinations thereof. At least one UE may be in communication with the first base station and the second base station via a wireless communication link of the millimeter wave wireless communication system. The method may include establishing a return communication link with the second base station based at least in part on the discovery procedure.

[00015] In some examples, the return communication link may be a wireless return communication link established via the millimeter wave wireless communication system. The method may include performing one or more coordination functions with the second base station via the return communication link. The timing parameter may be based at least in part on a frame timing for communications associated with the second base station of the millimeter wave wireless communications system. The propagation parameter may be based at least in part on a beamforming pattern for communication between the first base station and the second base station.

[00016] In a second illustrative set of examples, an apparatus for wireless communication is described. The apparatus may include a first base station of a millimeter wave wireless communication system. The apparatus may include: a processor; memory in electronic communication with the processor; and instructions stored in memory. The instructions being executable by the processor for: determining, by a first base station of the millimeter wave wireless communication system, a timing parameter and a propagation parameter associated with a second base station of the millimeter wave wireless communication system; and performing a discovery procedure with the second base station based at least in part on the timing parameter and propagation parameter, wherein at least a portion of the discovery procedure is performed wirelessly via the millimeter wave wireless communication system.

[00017] In some systems, the apparatus may include processor-executable instructions for: identifying a network entity having a connection to the first base station and the second base station; and receiving information from the network entity indicative of at least one of the timing parameter, or propagation parameter, or a combination thereof. The apparatus may include processor-executable instructions for transmitting information to the network entity indicating a request to establish a return communication link with the second base station. The network entity may be connected to the first base station and the second base station via a wired communication link. The network entity may be connected to the first base station and the second base station via a wireless communication link associated with a third base station of a millimeter wave wireless communication system.

[00018] In some examples, information received from the network entity indicative of at least one of the timing parameter or the propagation parameter is based at least in part on a previous return communication link from the first base station or second base station, or a geographic location of the first base station and second base station, or a message received from one or more user equipment (UEs) associated with communications through the first base station or second base station or combinations thereof. The information received from the network entity may include an indication of a timing window parameter associated with a timing window for attempting to perform the discovery procedure, a search beam parameter associated with a number of beams being transmitted by the second base station, a sequence parameter associated with a transmission sequence of the second base station or combinations thereof, a base station capabilities parameter identifying one or more capabilities of the second base station, or combinations thereof.

[00019] In some examples, the apparatus may include instructions executable by the processor to: refrain, by the first base station, from transmitting a synchronization signal during a synchronization period; and monitoring, by the first base station during the synchronization period, relative to a synchronization signal transmitted by the second base station. The apparatus may include processor-executable instructions to, after determining that the second base station has transmitted the synchronization signal, initiate the discovery procedure based at least in part on the transmitted synchronization signal. The message for the second base station to initiate the discovery procedure may be sent over a directional random access channel (DRACH). The apparatus may include processor-executable instructions for determining, by the first base station, a predetermined frequency associated with refraining from transmitting the synchronization signal and monitoring for transmission of the synchronization signal from the second base station.

[00020] In some examples, the predetermined periodicity is determined based at least in part on information received from a network entity. The synchronization signal transmitted from the second base station may include a directional primary synchronization signal (DPSS). The apparatus may include processor-executable instructions for determining, by the first base station, that the at least one user equipment (UE) is in communication with the first base station and the second base station; and relaying one or more messages to the second base station through the at least one UE to determine at least one of the timing parameter or propagation parameter associated with the second base station.

[00021] In some examples, the apparatus may include processor-executable instructions for: receiving one or more messages from the UE including information associated with the second base station; and determining execution of the discovery procedure based at least in part on one or more messages received from the UE. Information received from the UE associated with the second base station may include an indication of a timing window parameter associated with a timing window for attempting to perform the discovery procedure, a search beam parameter associated with a quantity of beams being transmitted by the second base station, a sequence parameter associated with a transmission sequence of the second base station, a base station capabilities parameter identifying one or more capabilities of the second base station, or combinations thereof.

[00022] In some examples, at least one UE is in communication with the first base station and the second base station via a wireless communication link of the millimeter wave wireless communication system. The apparatus may include processor-executable instructions for establishing a return communications link with the second base station based at least in part on the discovery procedure. The return communication link may be a wireless return communication link established via the millimeter wave wireless communication system. The apparatus may include processor-executable instructions to perform one or more coordination functions with the second base station via the return communication link.

[00023] In some examples, the timing parameter is based at least in part on a frame timing for communications associated with the second base station of the millimeter wave wireless communications system. The propagation parameter may be based at least in part on a beamforming pattern for communication between the first base station and the second base station.

[00024] In a third illustrative set of examples, an apparatus for wireless communication is described. The apparatus may include a first base station of a millimeter wave wireless communication system. The apparatus may include: means for determining, by a first base station of the millimeter wave wireless communication system, a timing parameter and a propagation parameter associated with a second base station of the millimeter wave wireless communication system; and means for performing a discovery procedure with the second base station based at least in part on the timing parameter and propagation parameter, wherein at least a portion of the discovery procedure is performed wirelessly via the wave wireless communication system millimeters.

[00025] In some systems, the apparatus may include means for identifying a network entity having a connection to the first base station and the second base station; and means for receiving information from the network entity indicative of at least one of the timing parameter, or propagation parameter, or a combination thereof. The apparatus may include means for transmitting information to the network entity indicating a request to establish a return communication link with the second base station.

[00026] In a fourth illustrative set of examples, a non-transitory computer-readable medium that stores computer-executable code for wireless communication is described. Code executable by a processor for: determining, by a first base station of the millimeter wave wireless communication system, a timing parameter and a propagation parameter associated with a second base station of the millimeter wave wireless communication system; and performing a discovery procedure with the second base station based at least in part on the timing parameter and propagation parameter, wherein at least a portion of the discovery procedure is performed wirelessly via the millimeter wave wireless communication system.

[00027] The above has very broadly outlined the characteristics and technical advantages of examples according to the disclosure so that the detailed description that follows can be better understood. Additional features and benefits will be described below. The specific design and examples disclosed can be readily used as a basis for modifying or designing other structures to accomplish the same purposes as the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in relation to the attached figures. Each of the figures is provided for purposes of illustration and description only, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[00028] A further understanding of the nature and advantages of the present invention can be achieved by reference to the following drawings. In the attached figures. Similar components or features may have the same reference label. Furthermore, multiple components of the same type can be distinguished by following the reference label by a dash and a second label that distinguishes between similar components. If only the first reference label is used in the specification, the description is applicable to any of the similar components having the same first reference label independent of the second label.

[00029] Figure 1 shows a block diagram of a wireless communication system, in accordance with various aspects of the present disclosure;

[00030] Figure 2 shows a swim diagram illustrating aspects of discovery operations in wireless communication, in accordance with various aspects of the present disclosure;

[00031] Figure 3 shows a swim diagram illustrating aspects of discovery operations in wireless communication, in accordance with various aspects of the present disclosure;

[00032] Figure 4 shows a swim diagram illustrating aspects of discovery operations in wireless communication, in accordance with various aspects of the present disclosure;

[00033] Figure 5 shows a diagram of aspects of an example discovery operation in wireless communication, in accordance with various aspects of the present disclosure;

[00034] Figure 6 shows a block diagram of an apparatus for use in wireless communication, in accordance with various aspects of the present disclosure;

[00035] Figure 7 shows a block diagram of an apparatus for use in wireless communication, in accordance with various aspects of the present disclosure;

[00036] Figure 8 shows a block diagram of a base station (for example, a base station that forms part or all of an eNB) for use in wireless communication, in accordance with various aspects of the present disclosure;

[00037] Figure 9 is a flowchart illustrating an example of a method for wireless communication in accordance with various aspects of the present disclosure;

[00038] Figure 10 is a flowchart illustrating another example of a method for wireless communication, in accordance with various aspects of the present disclosure; It is

[00039] Figure 11 is a flowchart illustrating another example of a method for wireless communication, in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION

[00040] Next generation cellular communication systems can utilize mmW wireless communication channels. Such mmW communication channels may involve using frequencies in the 20+ GHz range, which requires additional considerations in the development and deployment of infrastructure components. For example, mmW wireless links tend to have a smaller geographic coverage area and often require the use of directional transmissions. To provide large-scale coverage, a denser population of mmW base stations can be deployed, relative to traditional macro base stations for existing cellular communication systems. In some environments, it may not be reasonable from a cost and/or feasibility perspective to deploy high-speed wired communications links to every mmW base station. For example, not every deployment location will be suitable for a strong communications link between the mmW base station and a network entity. Such mmW base stations with limited or no direct links to a network entity will therefore establish direct links with one or more neighboring mmW base stations to access network functionality and will perform traditional backhaul operations. Discovery of such neighboring base stations, however, can be problematic in a mmW infrastructure due to limited (or no) access to a network entity.

[00041] In accordance with aspects of the present disclosure, in high frequency systems (e.g., millimeter wave communication systems), a base station may determine certain communication parameters associated with a second base station to initiate a discovery procedure with the second base station. For example, given the directional nature of mmW communications, a first base station may determine a propagation parameter associated with the second base station, e.g., knowing which direction the second base station is relative to the first base station. Additionally or alternatively, the first base station may determine a timing parameter associated with the second base station, for example, a timing indication of synchronization signal transmission by the second base station. The propagation and timing parameters may provide sufficient information to the first base station to initiate a discovery procedure with the second base station. During the discovery procedure, the first base station may determine any remaining communication parameters necessary to establish a return link with the second base station, e.g., frame timing and alignment information, MCS schemes, channel availability information, base station capabilities information, etc.

[00042] The following description provides examples and is not limiting the scope, applicability or examples set forth in the claims. Changes may be made to the function and arrangement of discussed elements without departing from the scope of the disclosure. Various examples may omit, replace, or add various procedures or components as appropriate. For example, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in other examples.

[00043] Figure 1 illustrates an example of a wireless communication system 100 in accordance with various aspects of the disclosure. The wireless communication system 100 includes base stations 105, UEs 115, and a core network 130. The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other functions. access, routing or mobility. The base stations 105 interface with the core network 130 via return links 132 (e.g., S1, etc.) and may perform radio configuration and programming for communication with the UEs, or may operate under the control of a controller base station (not shown). In various examples, base stations 105 may communicate, directly or indirectly (e.g., via core network 130), with each other via return links 134 (e.g., X1, etc.) which may be wired communication links. or wireless. In some examples, certain base stations 105 may have no (or limited) connection to the core network 130 and instead rely on a direct wireless connection with a neighboring base station 105 to perform discovery and return operations.

[00044] The base stations 105 may communicate wirelessly with the UEs 115 via one or more base station antennas. Each of the base station locations 105 may provide communications coverage for a respective geographic coverage area 110. In some examples, the base stations 105 may be referred to as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, eNodeB (eNB), native NodeB, a native eNodeB, or some other suitable terminology. The geographic coverage area 110 for a base station 105 may be divided into sectors comprising only a portion of the coverage area (not shown). The wireless communication system 100 may include base stations 105 of different types (e.g., macro and/or small cell base stations). There may be 110 overlapping geographic coverage areas for different technologies.

[00045] In some examples, the wireless communication system 100 is an LTE/LTE-A network. In LTE/LTE-A networks, the term developed node B (eNB) may be used generally to describe the base stations 105, while the term UE may be used generally to describe the UEs 115. The wireless communication system 100 It can be a heterogeneous LTE/LTE-A network in which different types of eNBs provide coverage for various geographic regions. For example, each eNB or base station 105 may provide communications coverage for a macro cell, a small cell, and/or other cell types. The term “cell” is a 3GPP term that can be used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (e.g. sector, etc.) of a carrier or station basis, depending on the context.

[00046] A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell is a base station with lower power, as compared to a macro cell, which can operate in the same or different frequency bands (e.g., licensed, unlicensed, etc.) as macro cells. Small cells may include pico cells, femto cells, and micro cells according to various examples. A pico cell can cover a smaller geographic area and can allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell may also cover a relatively small geographic area (e.g., a house) and may provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in the house, and similar). An eNB for a macro cell can be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a native eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells (e.g., component carriers).

[00047] The wireless communication system 100 may support synchronous or asynchronous operation. For synchronous operation, base stations may have similar frame timing, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, base stations may have different frame timing, and transmissions from different base stations may not be time aligned. The techniques described here can be used for synchronous or asynchronous operations.

[00048] Communication networks that can accommodate some of the various examples disclosed may be packet-based networks that operate according to a layered protocol stack. At the user plane, communications at the Packet or Bearer Data Convergence Protocol (PDCP) layer can be IP-based. A radio link control (RLC) layer can perform packet segmentation and reassembly to communicate over logical channels. A media access control (MAC) layer can perform priority handling and multiplexing of logical channels on transport channels. The MAC layer can also use hybrid ARQ (HARQ) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and base stations 105 or core network 130 supporting radio bearers for data of user plan. At the physical layer (PHY), transport channels can be mapped to physical channels.

[00049] The UEs 115 may be dispersed throughout the wireless communications system 100, and each UE 115 may be stationary or mobile. A UE 115 may also include or be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device , a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a telephone handset, a user agent, a mobile client, a customer or some other suitable terminology. A UE 115 may be a cellular telephone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless telephone, a loop station wireless location (WLL) or similar. A UE may be capable of communicating with various types of base stations and network equipment including macro eNBs, small cell eNBs, relay base stations, and the like.

[00050] The communication links 125 shown in the wireless communication system 100 may include uplink (UL) transmissions from a UE 115 to a base station 105 and/or downlink transmissions (DL) from a base station 105 to a UE 115. Downlink transmissions may also be called forward link transmissions while uplink transmissions may also be called reverse link transmissions. Each communication link 125 may include one or more carriers, where each carrier may be a signal composed of multiple subcarriers (e.g., waveform signals of different frequencies) modulated in accordance with the various radio technologies described above. Each modulated signal can be sent on a different subcarrier and can carry control information (e.g. reference signals, control channels, etc.), overhead information, user data, etc. Communication links 125 may transmit bidirectional communications using FDD (e.g., using paired spectrum resources) or TDD (e.g., using unpaired spectrum resources) operation. Frame structures for FDD (e.g. frame structure type 1) and TDD (e.g. frame structure type 2) can be defined.

[00051] In some embodiments of system 100, base stations 105 and/or UEs 115 may include multiple antennas to employ antenna diversity schemes to improve the quality and reliability of communication between base stations 105 and UEs 115. Additionally or alternatively, stations base 105 and/or UEs 115 may employ multiple input multiple output (MIMO) techniques that can take advantage of multipath environments to transmit multiple spatial layers carrying the same or different encoded data.

[00052] The wireless communication system 100 may support operation on multiple cells or carriers, a feature that may be referred to as carrier aggregation (CA) or multi-carrier operation. A carrier can also be referred to as a component carrier (CC), a layer, a channel, etc. The terms “carrier”, “component carrier”, “cell” and “channel” may be used interchangeably in the present invention. A UE 115 may be configured with multiple downlink CCs and one or more uplink CCs for carrier aggregation. Carrier aggregation can be used with FDD and TDD component carriers.

[00053] Wireless communication system 100 may operate in an ultra-high frequency (UHF) frequency region using frequency ranges of 700 MHz to 2600 MHz (2.6 GHz), although in some cases WLAN networks may use frequencies as high as 4 GHz. This region may also be known as the decimeter band, as the wavelengths range from approximately one decimeter to one meter in length. UHF waves can propagate primarily by line of sight and can be blocked by buildings and environmental features. However, the waves can penetrate walls sufficiently to provide service to internally located UEs 115. Transmission of UHF waves is characterized by smaller antennas and shorter range (e.g. less than 100 km) compared to transmission using the lower frequencies (and longer waves) of the high frequency (HF) or frequency portion of the spectrum. very high (VHF). In some cases, the wireless communication system 100 may also utilize extremely high frequency (EHF) portions of the spectrum (e.g., from 30 GHz to 300 GHz). This region may also be known as the millimeter wave (or mmW) band, since the wavelengths range from approximately one millimeter to one centimeter in length. Therefore, EHF antennas can be smaller and more closely spaced than UHF antennas. In some cases, this may facilitate the use of antenna arrays in a UE 115 (e.g., for directional beamforming). However, EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than UHF transmissions.

[00054] The wireless communication system 100 may support discovery procedures for millimeter wave communications. For example, a millimeter wave base station 105 may have no (or limited) connectivity with the core network 130 and therefore perform a discovery procedure with a neighboring millimeter wave base station 105 to establish a return link ( e.g., neighboring millimeter wave base station 105 may have robust connectivity with multiple network components). The first millimeter wave base station 105 may determine a propagation parameter and/or a timing parameter for the second (or neighboring) millimeter wave base station. The timing and propagation parameter may provide sufficient information for the first millimeter wave base station 105 to attempt to detect a synchronization signal or beacon from the second millimeter wave base station. The first millimeter wave base station 105 may initiate the discovery procedure based on the timing and/or propagation parameters.

[00055] In some examples, the first millimeter wave base station 105 may determine timing and propagation parameters by accessing a network entity, for example, using a limited or restricted link to the network entity. For example, the first millimeter wave base station 105 may send a message over the limited link to the network entity requesting information associated with neighboring base stations. The network entity may respond by sending timing and/or propagation parameters. Another example may include the first millimeter wave base station 105 identifying a UE 115 in communication with the second millimeter wave base station. The first millimeter wave base station 105 may utilize communication link through the shared UE 115 to determine timing and/or propagation parameters. Other examples may include the first millimeter wave base station 105 blindly sensing timing and/or propagation parameters based on resource division schemes, e.g., dividing access resources and return resources. The first millimeter wave base station 105 may initiate a discovery procedure with the second millimeter wave base station using the determined parameters and, based on the discovery procedures, determine additional communication parameters associated with the second millimeter wave base station used to establish a return communication link.

[00056] Figure 2 is a swim diagram 200 illustrating aspects of discovery operations, in accordance with various aspects of the present disclosure. Diagram 200 may illustrate aspects of system 100 described with reference to Figure 1. Diagram 200 includes a first millimeter wave (mmW) base station 205 and a second mmW base station 210. The millimeter wave base station first mmW base station 205 and/or the second mmW base station 210 may be examples of one or more of the base stations 105 described above with respect to Figure 1. In general, diagram 200 illustrates aspects of implementing discovery operations in millimeter wave communication systems. In some examples, a system device such as one of the base stations 105 may execute one or more sets of codes to control functional elements of the device to perform some or all of the functions described below.

[00057] In block 215, the first mmW base station 205 may determine a timing parameter and a propagation parameter associated with the second base station 210. The timing parameter may include various timing components associated with communication with the second mmW base station 210. For example, the timing component may include information associated with programming for beacon signals and/or synchronization from the second base station 210. Other examples of timing parameters may include, but are not limited to, timing and alignment information. of frame, common synchronization timing information for the second base station mmW 210, a timing window parameter associated with attempting to perform the discovery procedure with the second base station mmW 210, and the like. The propagation parameter may include information associated with directional communications. Example propagation parameters may include, but are not limited to, a beamforming direction parameter based on the geographic locations of the first mmW base station 205 and second mmW base station 210, a beam count parameter associated with one or more detection beams (e.g. beacons and/or synchronization signals) transmitted by the second base station mmW 210 and the like.

[00058] In block 220, the first mmW base station 205 may initiate a discovery procedure 225 with the second mmW base station 210. The discovery procedure 225 may be based on the determined timing parameter, the determined propagation parameter, or a combination both. At least a portion of the discovery procedure 225 may be performed wirelessly via the mmW wireless communication channel.

[00059] Figure 3 is a swim diagram 300 illustrating aspects of discovery operations, in accordance with various aspects of the present disclosure. Diagram 300 may include aspects of the system 100 described with reference to Figure 1. Diagram 300 includes a first millimeter wave (mmW) base station 305, a network entity 310, and a second mmW base station 315. The first mmW base station 305 and/or the second mmW base station 315 may be examples of one or more of the base stations 105 described above with respect to Figure 1. The network entity 310 may be an example of the core network 130 described above with respect to Figure 1. In general, diagram 300 illustrates aspects of implementing network-aided discovery operations in millimeter-wave communication systems. In some examples, a system device such as one of the base stations 105 may execute one or more sets of codes to control functional elements of the device to perform some or all of the functions described below.

[00060] In block 320, the first mmW base station 305 may identify a connection to the network entity 310. The connection may be a direct connection to the network entity 310 and/or an indirect connection through a third mmW base station (not shown). For a direct connection, the first mmW base station 305 may have a limited connection that supports minimal data communications, for example, over a low bandwidth connection and/or a restricted connection. The first mmW base station 305 may identify the connection to the network entity 310 that is also connected to the second mmW base station 315.

[00061] In block 325, the first mmW base station 305 may receive parameters 330 from the network entity 310. The parameters may include at least one of a timing parameter associated with the second mmW base station 315, an associated propagation parameter to the second base station mmW 315, or both parameters. In some examples, the first mmW base station 305 may send a message to the network entity 310 indicating the need to perform a discovery procedure with the second mmW base station 315 (or any neighboring mmW base station). The network entity 310 may store information associated with mmW base stations, e.g., geographic location information, operational capabilities, communication parameters, etc., and identify the second mmW base station 315 as a candidate for discovery and return operations to the first mmW base station 305. Therefore, the network entity 310 may select and send parameters 330 to the first mmW base station 305 associated with the second mmW base station 315.

[00062] As previously discussed, the parameters sent may include a timing parameter and a propagation parameter associated with the second mmW base station 315. The timing parameter may include various timing components associated with communication with the second mmW base station 315. The propagation parameter may include information associated with directional communications to the second mmW base station 315.

[00063] In block 335, the first mmW base station 305 may initiate and execute a discovery procedure 340 with the second mmW base station 315. The discovery procedure 340 may be based on the timing parameter, propagation parameter, or a combination of both. At least a portion of the discovery procedure 340 may be performed wirelessly via the mmW wireless communication channel. The discovery procedure may, in some examples, allow the first mmW base station 305 to determine additional (or any missing) communication parameters to communicate with the second mmW base station 315, e.g., MCS parameters, channel settings and availability, capacity parameters, etc. Accordingly, the first mmW base station 305 may, based at least in part on the discovery procedure, establish a return link with the second mmW base station 315 to perform return operations.

[00064] Figure 4 is a swim diagram 400 illustrating aspects of discovery operations, in accordance with various aspects of the present disclosure. Diagram 400 may illustrate aspects of system 100 described with reference to Figure 1. Diagram 400 includes a first millimeter wave (mmW) base station 405, a UE 410, and a second mmW base station 415. The first mmW base station 405 and /or the second mmW base station 415 may be examples of one or more of the base stations 105 described above with respect to Figure 1. The UE 410 may be an example of one or more of the UEs 115 described above with respect to Figure 1. In Overall, diagram 400 illustrates aspects of implementing UE-aided discovery operations in millimeter-wave communication systems. In some examples, a system device, such as one of the base stations 105 and/or UEs 115, may execute one or more sets of codes to control functional elements of the device to perform some or all of the functions described below.

[00065] In block 420, the first mmW base station 405 may identify a common connection between the first mmW base station 405, the UE 410 and the second mmW base station 415. The common connection may be a direct connection to the second base station mmW 415 through UE 410 and/or an indirect connection through one or more additional UEs (not shown). In general, the common connection through the UE 410 may support limited communication between the first mmW base station 405 and the second mmW base station 415. In some examples, the UE 410 may send a neighbor cell list (NCL) to the first station mmW base including information identifying the second mmW base station 415, for example, an identification information associated with the second mmW base station 415.

[00066] In block 425, the first mmW base station 405 may relay a request to the second mmW base station 415 via the UE 410. For example, the first mmW base station 405 may send a message 430 to the UE 410 requesting that the UE 410 send the message to the second mmW base station 415. The UE 410 may send the message 435 to the second mmW base station 415. In general, the message sent may include a request for the timing parameter, the propagation parameter or both parameters associated with the second base station mmW 415.

[00067] The second mmW base station 415 may send a response 440 to the request from the first mmW base station 405 which is retransmitted 445 via the UE 410. Therefore, in block 450 the first mmW base station 405 may determine the parameter timing parameter, the propagation parameter, or both parameters associated with the second mmW base station 415. In block 455, the first mmW base station 405 may initiate and execute a discovery procedure 460 with the second mmW base station 415. The discovery 460 may be based on the timing parameter, propagation parameter, or a combination of both. At least a portion of the discovery procedure 460 may be performed wirelessly via the mmW wireless communication channel. The discovery procedure may, in some examples, allow the first mmW base station 405 to determine additional (or any missing) communication parameters to communicate with the second mmW base station, e.g., MCS parameters, channel settings and availability, parameters capacity, etc. Accordingly, the first mmW base station 405 may, based at least in part on the discovery procedure, establish a return link with the second mmW base station to perform return operations.

[00068] Figure 5 shows a diagram 500 of aspects of an example discovery operation in wireless communication, in accordance with various aspects of the present disclosure. Diagram 500 may illustrate aspects of the system 100 described with reference to Figure 1. In general, diagram 500 illustrates an example of one or more aspects of discovery procedures between a first mmW base station and a second neighboring mmW base station. In some examples, a system device, such as one or more mmW base stations, such as base stations 105, first mmW base stations 205, 305 and/or 405, described with reference to figures 1, 2, 3 and/or 4, may execute one or more sets of codes to control functional elements of the device to perform some or all of the functions illustrated with respect to diagram 500.

[00069] Typical access procedures between a mmW base station and UEs in its coverage area may include multi-beacon transmissions, synchronization signals, etc., from the base station followed by access requests from the UEs. UEs can locate a base station by detecting the synchronization signal(s), from which the UEs acquire the base station identification code (cell ID), system timing information, information frame alignment, etc. for example, the first mmW base station may transmit one or more synchronization signals over a directional primary synchronization channel (DPSS) during a synchronization period 510 to UEs to detect their presence. The synchronization signal may include various attributes associated with the first mmW base station and used by the UE to collect additional parameters for communicating with the first mmW base station. The first mmW base station may then typically listen to (or monitor) the response from the UEs over a directional random access channel (DRACH) during an access period 505. Similarly, the second mmW base station sends its own signals of synchronization during synchronization periods 520 and then monitors for responses from UEs in its coverage area during access periods 515.

[00070] In some examples, mmW base stations may perform over-the-air discovery procedures (e.g., blind discovery procedures) by provisioning certain access resources for discovery operations. For example, the first mmW base station may switch roles, not transmit during its synchronization period 510, and instead listen for synchronization signals transmitted from the second mmW base station. As illustrated in diagram 500, the first mmW base station may refrain from transmitting its synchronization signal during synchronization period 510-a and instead listen for synchronization signals transmitted from the second mmW base station during its synchronization period 520-a.

[00071] Similarly, the first mmW base station may re-provision access resources to transmit its synchronization signals during an access period 505. As illustrated in diagram 500, the first mmW base station may refrain from listening during access period 505- e and instead transmit its synchronization signals during the 505-e access period. the second mmW base station may then detect the synchronization signal transmissions during its access period 515-e. Therefore, diagram 500 illustrates examples of provisioning schemes that can be employed for discovery operations in mmW wireless communication systems.

[00072] According to certain aspects, the frequency of such resource provisioning may be relatively low. For example, mmW base stations may switch roles only occasionally, or at a periodicity at or below a threshold level, to provide sufficient access opportunities for the UEs in their respective coverage areas.

[00073] In some examples, the timing parameter determined by the first mmW base station may correspond to the synchronization period and/or access period for the second mmW base station. For example, the first mmW base station may determine such timing parameters based on information received from a network entity, through a UE communicating with the first and second mmW base stations, and/or using a blind discovery. As also illustrated in diagram 500, the first and second mmW base stations may not share a common timing synchronization, that is, be out of sync with each other. Although the described blind discovery procedure allows the first mmW base station to determine the timing parameter for the second mmW base station, the first mmW base station may have already determined the timing parameter using any of the described techniques and therefore provision capabilities based at least in part on the timing parameter associated with the second mmW base station.

[00074] Furthermore, the first mmW base station may perform such a discovery procedure to determine (or after having determined) the timing parameter with or without the propagation parameter associated with the second mmW base station. For example, the first mmW may attempt to detect synchronization signal transmissions from the second mmW base station using a scan pattern where certain antennas are configured for directional communications, e.g., beamforming. The first mmW base station may listen in a first direction during a first synchronization period, e.g., synchronization period 510-a, and then listen in a second direction during a subsequent synchronization period. Therefore, the first mmW base station can detect synchronization signals transmitted from the second mmW base station (as well as other neighboring mmW base stations) without knowing the direction (e.g., geographic location) of the base stations.

[00075] Figure 6 shows a block diagram 600 of an apparatus 605 for use in wireless communication, in accordance with various aspects of the present disclosure. In some examples, the apparatus 605 may be an example of aspects of one or more of the base stations 105, 205, 305 and/or 405 described with reference to figures 1, 2, 3 and 4, respectively. In some examples, the apparatus 605 may be part of or include an LTE/LTE-A eNB and/or an LTE/LTE-A base station. The apparatus 605 may be a base station operating in a mmW wireless communication system. Apparatus 605 may also be a processor. Apparatus 605 may include a receiver 610, a discovery manager 615, and/or a transmitter 620. Each of these modules may be in mutual communication.

[00076] The components of apparatus 605 may, individually or collectively, be implemented using one or more ASICS adapted to perform some or all of the applicable hardware functions. Alternatively, the functions may be performed by one or more other processing units (or cores) on one or more integrated circuits. In other examples, other types of integrated circuits may be used (e.g., platform/structured ASICs, FPGAs, and other semi-custom ICs), which may be programmed in any manner known in the art. The functions of each component can also be implemented, in whole or in part, with instructions embedded in a memory, formatted to be executed by one or more specific or general application processors.

[00077] In some examples, the receiver 610 may include at least one radio frequency (RF) receiver, such as an RF receiver operable to receive one or more messages associated with a discovery procedure for the apparatus 605. The receiver 610 may be used to receive various types of data and/or control signals (i.e., transmissions) through one or more communication links of a wireless communication system, such as one or more communication links of the wireless communication system 100 described with reference to figure 1.

[00078] In some examples, transmitter 620 may include at least one RF transmitter, such as at least one RF transmitter operable to transmit one or more messages associated with a discovery procedure to apparatus 605. Transmitter 620 may be used to transmit various types of data and/or control signals (i.e., transmissions) through one or more communication links of a wireless communication system, such as one or more communication links of the wireless communication system 100 described with reference to figure 1.

[00079] In some examples, the discovery manager 615 may monitor, control, or otherwise manage one or more aspects of a discovery procedure for the apparatus 605. For example, the apparatus 605 may be a mmW base station that seeks to initiate and performing a discovery procedure with a second mmW base station to establish a return link for return operations. The discovery manager 615 may determine a timing parameter, a propagation parameter, or both timing and propagation parameters associated with the second mmW base station. The discovery manager 615 may also perform a discovery procedure with the second mmW base station based on the timing parameter and propagation parameter. At least a portion of the discovery procedure may be performed wirelessly via the mmW wireless communication system.

[00080] In some examples, the discovery manager 615 may manage aspects of establishing a return communication link with the second base station mmW based on the discovery procedure, e.g., a wireless return communication link through the system mmW wireless communication. The apparatus 605 can perform various coordination functions with the second mmW base station via the return communication link.

[00081] In some examples, discovery manager 615 may determine a timing parameter associated with the second mmW base station, where the timing parameter is based on a frame timing attribute for communicating with the second mmW base station. Furthermore, the propagation parameter may, in certain examples, be based on a beamforming pattern for communicating with the second mmW base station.

[00082] Figure 7 shows a block diagram 700 of apparatus 605-a for use in wireless communication, in accordance with various aspects of the present disclosure. In some examples, the apparatus 605-a may be an example of aspects of one or more of the base stations 105, 205, 305 and/or 405 described with reference to Figures 1, 2, 3 and 4, respectively. In some examples, the apparatus 605-a may be an example of the apparatus 605 described with reference to Figure 6. In some examples, the apparatus 605-a may be part of or include an LTE/LTE-A eNB and/or a station LTE/LTE-A base. apparatus 605-a may be a base station operating in a mmW wireless communication system. Apparatus 605-a may also be a processor. Apparatus 605-a may include a receiver 610-a, a discovery manager 615-a, and/or a transmitter 620-a. each of these modules can be in communication with each other. Receiver 610-a and transmitter 620-a may be examples of and perform the functions of receiver 610 and transmitter 620, respectively, described with reference to FIG. 6. In some examples, discovery manager 615-a may be an example of the 6 and may include a timing and propagation manager 705, a link manager 710 and/or discovery procedure manager 715.

[00083] In some examples, the timing and propagation manager 705 may monitor, control, or otherwise manage aspects of determining a timing parameter and a propagation parameter associated with communication with a second mmW base station. For example, the timing parameter may be based on a frame timing attribute to communicate with the second mmW base station. Other examples of timing parameters may include beam sequencing timing information associated with one or more synchronization periods and/or access periods for the second mmW base station. The propagation parameter may, in certain examples, be based on a beamforming pattern for communicating with the second mmW base station.

[00084] In some examples, the timing and propagation manager 705 may cooperate with the link manager 710 to determine timing and propagation parameters. For example, the timing and propagation manager 705 may, individually or in cooperation with one or more other components of the apparatus 605-a, cause the apparatus 605-a to refrain from transmitting a synchronization signal during a synchronization period and, instead, monitor during the synchronization period against a synchronization signal transmitted by the second base station. When it is determined that the second base station has transmitted a synchronization signal, the timing and propagation manager 705 may initiate the discovery procedure based at least in part on the transmitted synchronization signal. In some examples, the message for the second base station to initiate the discovery procedure may be sent over a downlink directional random access channel (DRACH).

[00085] In some examples, the timing and propagation manager 705 may determine a predetermined periodicity associated with refraining from transmitting the synchronization signal and monitoring relative to the transmission of the synchronization signal from the second base station. Periodicity may be determined, at least in some examples, based at least in part on information received from a network entity. In some examples, the synchronization signal transmitted from the second base station may be a directional primary synchronization signal (DPSS).

[00086] Link manager 710 may monitor, control or otherwise manage one or more aspects of identifying a link which may, in certain examples, be leveraged to determine aspects of the timing parameter and/or propagation parameter for the apparatus 605-a. In one example, the link manager 710 may identify a network entity having a connection to the apparatus 605-a and the second ase mmW station. The link manager 710 may receive information from the network entity indicative of at least one of the timing parameter, or the propagation parameter, or a combination thereof. For example, link manager 710 may, individually or in cooperation with transmitter 620-a, transmit information to the network entity indicating a request to establish a return communication link with the second base station.

[00087] In some examples, the link manager 710 may determine that the network entity is connected to the apparatus 605-a and the second base station via a wired communication link, for example, an Ethernet communication link. Additionally or alternatively, the link manager 710 may determine that the network entity is connected to the apparatus 605-a and the second base station via a wireless communication link associated with a third base station of the millimeter wave wireless communication system. That is, apparatus 605-a may be in communication, for example, via a feedback link, with a third mmW base station and leverage the link to determine aspects of the timing parameter and/or propagation parameter.

[00088] In some examples, information received from the network entity indicative of at least one of the timing parameter or propagation parameter may be based on a previous return communication link from apparatus 605-a or second base station, or a geographic location of the apparatus 605-a and second base station, or a message received from one or more user equipment (UEs) associated with communications through the apparatus 605-a or second base station, or combinations thereof. Furthermore, the information received from the network entity may also include additional communication parameters associated with the second mmW base station. Examples include, but are not limited to, an indication of a timing window parameter associated with a timing window to attempt to perform the discovery procedure, a search beam parameter associated with a number of beams being transmitted by the second station base, a sequence parameter associated with a transmission sequence of the second base station, a base station capabilities parameter identifying one or more capabilities of the second base station, or combination thereof.

[00089] In some examples, link manager 710 may determine that at least one user equipment (UE) is in communication with apparatus 605-a and the second base station and relay one or more messages to the second base station via at least one UE to determine at least one of the timing parameter or propagation parameter associated with the second base station. Accordingly, link manager 710 may, individually or in cooperation with receiver 610-a, receive one or more messages from the UE including information associated with the second base station, and determine to execute the discovery procedure based on at least in part in one or more messages received from the UE.

[00090] In some examples, the information received from the UE associated with the second base station may also include an indication of a timing window parameter associated with a timing window for attempting to perform the discovery procedure, a beam parameter search associated with a quantity of beams being transmitted by the second base station, a sequence parameter associated with a transmission sequence of the second base station, a base station capabilities parameter identifying one or more capabilities of the second base station, or combinations thereof. At least one UE may, in some examples, be in communication with the apparatus 605-a and the second base station via a wireless communication link of the millimeter wave wireless communication system.

[00091] Discovery procedure manager 715 may monitor, control, or otherwise manage aspects of performing a discovery procedure for apparatus 605-a. The discovery procedure may be performed with the second mmW base station and, in some examples, be performed wirelessly via the mmW wireless communication system. The discovery procedure manager 715 may utilize the timing parameter to determine a frame timing attribute for communicating with the second mmW base station. The discovery procedure manager 715 may utilize the timing parameter to determine a frame timing attribute for communicating with the second mmW base station, determine a pattern or timing of synchronization signal transmission from the second mmW base station, etc. . The discovery procedure manager 715 may utilize the propagation parameter to determine a beamforming direction for communication with the second mmW base station. Accordingly, the discovery procedure manager 715 may, individually or in cooperation with the other components of the apparatus 605-a, initiate and execute a discovery procedure with the second mmW base station to determine communication parameters associated with the establishment of a link. return communication to perform return operations.

[00092] Figure 8 shows a block diagram 800 of a base station 105-a (e.g., a base station that forms part or all of an eNB) for use in wireless communication, in accordance with various aspects of the present disclosure. In some examples, the base station 105-a may be an example of aspects of one or more of the base stations 105 described with reference to Figure 1, aspects of one or more of the first base stations 205, 305 and 405, described with reference to figures 2, 3 and 4, respectively, and/or aspects of one or more of the apparatus 605 when configured as a base station, as described with reference to figures 6 and/or 7. Base station 105-a may be configured to implement or facilitate at least some of the aspects and functions of the base station and/or apparatus described with reference to Figures 1-7.

[00093] Base station 105-a may include a base station processor 810, a base station memory 820, at least one base station transceiver (represented by base station transceiver 850), at least one base station antenna ( represented by base station antenna(s) 855), and/or a discovery manager 615-b. The base station 105-a may also include one or more of a base station communication manager 830 and/or a network communication manager 840. Each of these modules may be in communication with each other, directly or indirectly, through one or more plus 835 buses.

[00094] Base station memory 820 may include random access memory (RAM) and/or read-only memory (ROM). The base station memory 820 may store computer-executable, computer-readable software/firmware code 825 containing instructions that are configured to, when executed, cause the base station processor 810 to perform various functions described herein relating to wireless communication. (e.g., performing discovery operations on a millimeter-wave wireless communication system, etc.). Alternatively, the computer-executable, computer-readable software/firmware code 825 may not be directly executable by the base station processor 810, but be configured to cause the base station 105-a (e.g., when compiled and executed) perform many of the functions described here.

[00095] The base station processor 810 may include an intelligent hardware device, e.g., a central processing unit (CPU), a microcontroller, an ASIC, etc. The base station processor 810 may process information received through the base station transceiver 850, the base station communications manager 830, and/or the network communications manager 840. The base station processor 810 may also process information to be sent to transceiver 850 for transmission via antenna(s) 855, to base station communications manager 830 for transmission to one or more other base stations 105b and 105-c, and/or to the network communication 840 for transmission to a core network 845, which may be an example of one or more aspects of the core network 130 described with reference to FIG. 1. The base station processor 810 may handle, individually or with respect to the manager of discovery 615-b, various aspects of discovery procedures for base station 105-a.

[00096] The base station transceiver 850 may include a modem configured to modulate packets and provide the modulated packets to the base station antenna(s) 855 for transmission, and demodulate packets received from the antenna(s). base station transceiver 855. Base station transceiver 850 may, in some examples, be implemented as one or more base station transmitter modules and one or more separate base station receiver modules. The base station transceiver 850 may support communication in a first radio frequency spectrum band and/or a second radio frequency spectrum band. The base station transceiver 850 may be configured to communicate bidirectionally, via the antenna(s) 855, with one or more UEs or apparatus, such as one or more of the UEs 115 described with reference to FIGS. 1-5. Base station 105-a may, for example, include multiple base station antennas 855 (e.g., an antenna array). The base station 105-a can communicate with the core network 845 through the network communication module 840. The base station 105-a can also communicate with other base stations, such as the base stations 105-b and 105-c, using the 830 base station communication manager.

[00097] Discovery manager 615-b may be configured to perform and/or control some or all of the features and/or functions described with reference to Figures 1-7 relating to discovery operations for base station 105-a. In some examples, the discovery manager 615-b may determine timing and/or propagation parameters associated with a second mmW base station and perform a discovery procedure with the second mmW base station. The discovery manager 615-b, or portions thereof, may include a processor, and/or some or all of the functions of the discovery manager 615-b may be performed by the base station processor 810 and/or with respect to the base station processor 810. base station 810. In some examples, the discovery manager 615-b may be an example of the discovery manager 615 described with references to Figures 6 and/or 7. For example, the discovery manager 615-b may include a link 710-a and a discovery procedure manager 715-a, which may be examples of and perform the functions of the link manager 710 and the discovery procedure manager 715, respectively, described with reference to FIG. 7.

[00098] Figure 9 is a flowchart illustrating an example of a method 900 for wireless communication, in accordance with various aspects of the present disclosure. For clarity, method 900 is described below with reference to aspects of one or more of the base stations 105, 205, 305, 405 described with reference to Figures 1, 2, 3, 4 and 8, respectively, and/or aspects of a or more of the apparatus 605 described with reference to Figures 6 and 7. In some examples, a base station may execute one or more sets of codes to control functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may perform one or more of the functions described below using special purpose hardware.

[00099] In block 905, method 900 may include a first base station of a mmW wireless communication system determining a timing parameter and a propagation parameter associated with a second base station of the mmW wireless communication system. The timing parameter may include a frame timing attribute, a synchronization signal transmission timing attribute, and the like. The propagation parameter may include a beamforming parameter, a beam sequence, and the like, associated with communication with the second base station.

[000100] In block 910, method 900 may include the first base station performing a discovery procedure with the second base station based at least in part on the timing parameter and propagation parameter. In some examples, at least a portion of the discovery procedure may be performed wirelessly via the mmW wireless communication system. The discovery procedure may include the first base station determining additional communication parameters associated with communication with the second base station, e.g., MCS parameters, base station capability parameters, etc.

[000101] The operation(s) in block 905 and/or 910 may be performed using the discovery manager 615 described with reference to Figures 6-8.

[000102] In this way, method 900 can provide wireless communication. It should be noted that method 900 is only one implementation and that operations of method 900 may be rearranged or otherwise modified so that other implementations are possible.

[000103] Figure 10 is a flowchart illustrating an example of a method 1000 for wireless communication, in accordance with various aspects of the present disclosure. For clarity, method 1000 is described below with reference to aspects of one or more of the base stations 105, 205, 305, 405 described with reference to Figures 1, 2, 3, 4 and 8, respectively, and/or aspects of a or more of the apparatus 605 described with reference to Figures 6 and 7. In some examples, a base station may execute one or more sets of codes to control functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may perform one or more of the functions described below using special purpose hardware.

[000104] In block 1005, method 1000 may include a first base station of a mmW wireless communication system determining a timing parameter and a propagation parameter associated with a second base station of the mmW wireless communication system. The timing parameter may include a frame timing attribute, a synchronization signal transmission timing attribute, and the like. The propagation parameter may include a beamforming parameter, a beam sequence, and the like, associated with communication with the second base station.

[000105] In block 1010, method 1000 may include the first base station performing a discovery procedure with the second base station based at least in part on the timing parameter and propagation parameter. In some examples, at least a portion of the discovery procedure may be performed wirelessly via the mmW wireless communication system. The discovery procedure may include the first base station determining additional communication parameters associated with communication with the second base station, e.g., MCS parameters, base station capability parameters, etc.

[000106] In block 1015, method 1000 may include the first base station establishing a return communication link with the second base station based at least in part on the discovery procedure. For example, the discovery procedure may provide additional communication parameters to establish the return communication link via the mmW wireless communication system. The first base station can perform various coordination functions with the second base station via the return communication link.

[000107] The operation(s) in block 1005, 1010 and/or 1015 can be performed using the discovery manager 615 described with reference to FIGS. 6-8.

[000108] In this way, method 1000 can provide wireless communication. It should be noted that method 1000 is only one implementation and that operations of method 1000 may be rearranged or otherwise modified so that other implementations are possible.

[000109] Figure 11 is a flowchart illustrating an example of a method 1100 for wireless communication, in accordance with various aspects of the present disclosure. For clarity, method 1100 is described below with reference to aspects of one or more of the base stations 105, 205, 305, 405 described with reference to Figures 1, 2, 3, 4 and 8, respectively, and/or aspects of a or more of the apparatus 605 described with reference to Figures 6 and 7. In some examples, a base station may execute one or more sets of codes to control functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may perform one or more of the functions described below using special purpose hardware.

[000110] In block 1105, method 1100 may include a first base station of a mmW wireless communication system identifying a link in connection with the second base station of the mmW wireless communication system. In some examples, the link may include a wired and/or wireless link to a network entity, a third base station of the mmW wireless communication system, one or more UEs in communication with the first base station and the second base station. , or combinations thereof.

[000111] In block 1110, method 1100 may include the first base station by determining a timing parameter and a propagation parameter associated with the second base station. The first base station may determine timing and propagation parameters based on the identified link, for example, through one or more messages exchanged with, or forwarded over, the link.

[000112] In block 1115, method 1100 may include the first base station performing a discovery procedure with the second base station based at least in part on the timing parameter and propagation parameter. In some examples, at least a portion of the discovery procedure may be performed wirelessly via the mmW wireless communication system. The discovery procedure may include the first base station determining additional communication parameters associated with communication with the second base station, e.g., MCS parameters, base station capability parameters, etc.

[000113] The operation(s) in block 1105, 1110 and/or 1115 can be performed using the discovery manager 615 described with reference to figures 6-8.

[000114] In this way, method 1000 can provide wireless communication. It should be noted that method 1000 is only one implementation and that operations of method 1000 may be rearranged or otherwise modified so that other implementations are possible.

[000115] In some examples, aspects of two or more of methods 900, 1000, 1100 may be combined. It should be noted that methods 900, 1000, etc., are example implementations only, and that the operations of methods 900-1000 may be rearranged or otherwise modified so that other implementations are possible.

[000116] The techniques described here can be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other systems. The terms “system” and “network” are often used interchangeably. A CDMA system can implement a radio technology such as CDM2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. IS-2000 releases 0 and A are commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes wideband CDMA (WCDMA) and other CDMA variants. A TDMA system can implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA system can implement radio technology such as Ultra Mobile Broadband (UMB), Developed UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM™, etc. UTRA and E-UTRA are part of the universal Mobile Telecommunications System (UMTS). Long-Term Evolution 3GPP (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization called the “3rd Generation Society Project” (3GPP). CDMA2000 and UMB are described in documents from an organization called “3rd Generation Society Project 2” (3GPP2). The techniques described here can be used for the radio systems and technologies mentioned above as well as other radio systems and technologies, including cellular communications (e.g., LTE) over unlicensed and/or shared bandwidth. The description below, however, describes an LTE/LTE-A system for example purposes, and LTE terminology is used throughout much of the description below, although the techniques are applicable beyond LTE/LTE-A applications.

[000117] The detailed description set out above in relation to the attached drawings describes examples and does not represent the only examples that can be implemented or that are included within the scope of the claims. The terms “example” and “exemplary,” when used in this description, mean “to serve as an example, instance, or illustration” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the techniques described. These techniques, however, can be put into practice without these specific details. In some instances, well-known structures and apparatus are shown in block diagram form to avoid obscuring the concepts of the examples described.

[000118] Information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic particles or fields, optical particles or fields or any combination of the same.

[0001] The various illustrative logic blocks and components described in connection with the disclosure of the present invention can be implemented or executed with a general purpose processor, a digital signal processor (DSP), an ASIC, an FPGA or other programmable logic device , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described here. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration.

[000119] The functions described here can be implemented in hardware, software executed by a processor, firmware or any combination thereof. If implemented in software executed by a processor, the functions may be stored in or transmitted through as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above may be implemented using software running by a processor, hardware, firmware, wired connection, or combinations of any of these. Aspects implementing functions may also be physically located in various positions, including being distributed so that portions of functions are implemented in different physical locations. As used herein, including in the claims, the term “and/or”, when used in a list of two or more items, means that any one of the items listed may be employed by itself, or any combination of two or more of the items listed can be employed. For example, if a composition is described as containing components A, B and/or C, the composition may contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination. Also, as used herein, including in claims “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates a disjunctive list. so that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (that is, A and B and C).

[000120] Computer readable media includes both computer storage media and communication media including any media that facilitates transfer of a computer program from one location to another. Storage media can be any available media that can be accessed by a general purpose or special purpose computer. By way of example and not limitation, computer-readable media may comprise RAM, ROM, EEPROM, flash memory, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other media that may be used to load or store a medium of desirable program code in the form of instructions or data structures and that can be accessed by a general purpose or special purpose computer, or a general purpose or special purpose processor. Also, any connection is properly called a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL), or wireless technologies such as infrared, radio, and micro- waves, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of media. Disk and disc, as used here, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disc, and Blu-ray disc where disks typically reproduce data magnetically, while disks reproduce data optically with lasers. Combinations of the above are also included in the scope of computer-readable media.

[000121] The foregoing description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Accordingly, the disclosure should not be limited to the examples and designs described here, but the broadest scope compatible with the principles and new aspects disclosed here should be agreed upon.

Claims (4)

1. Method for wireless communication in a millimeter wave wireless communication system (1000), characterized by the fact that it comprises: refraining, by a first base station of the millimeter wave wireless communication system, from transmitting a synchronization signal during a synchronization period; monitoring, by the first base station of the millimeter wave wireless communication system during the synchronization period, by a synchronization signal transmitted by the second base station; determine (1005), by a first base station of the millimeter wave wireless communication system, based on the synchronization signal transmitted by the second base station, a timing parameter and a propagation parameter associated with the second base station of the communication system millimeter wave wireless; perform (1010), by the first base station of the millimeter wave wireless communication system, a discovery procedure with the second base station based at least in part on the timing parameter and propagation parameter, wherein at least a portion of the procedure Discovery is performed wirelessly via millimeter wave wireless communication system; and establishing (1015), by the first base station of the millimeter wave wireless communication system, a return communication link with the second base station based at least in part on the discovery procedure. 2. Method according to claim 1, characterized by the fact that it further comprises: determining, by the first base station, a predetermined periodicity associated with refraining from transmitting the synchronization signal. 3. First base station of a millimeter wave wireless communication system (1100), characterized in that it comprises: means for refraining from transmitting a synchronization signal during a synchronization period; means for monitoring during the synchronization period a synchronization signal transmitted by a second base station; means for determining (1110), by the first base station of the millimeter wave wireless communication system, based on the synchronization signal transmitted by the second base station, a timing parameter and a propagation parameter associated with the second base station of the millimeter wave wireless communication system. millimeter wave wireless communication; means for performing (1115), through the first base station of the millimeter wave wireless communication system, a discovery procedure with the second base station, based at least in part on the timing parameter and propagation parameter, wherein at least a portion of the discovery procedure is performed wirelessly via the millimeter wave wireless communication system; and means for establishing, by the first base station of the millimeter wave wireless communication system, a return communication link with the second base station, based at least in part on the discovery procedure. 4. Computer-readable memory comprising instructions stored therein that, when executed, cause a computer to perform the method as defined in any one of claims 1 and 2.