WO2016119199A1

WO2016119199A1 - Physical layer counting and bearer type selection

Info

Publication number: WO2016119199A1
Application number: PCT/CN2015/071912
Authority: WO
Inventors: Xipeng Zhu; Xiaoxia Zhang; Gavin Bernard Horn; Jun Wang; Naga Bhushan
Original assignee: Qualcomm Incorporated
Priority date: 2015-01-30
Filing date: 2015-01-30
Publication date: 2016-08-04

Abstract

A systems, methods, and/or devices for physical layer counting of user equipments (UEs) interested in one or more multimedia broadcast multicast service (MBMS) services, and selecting a bearer based on the physical layer counting. In some examples, a network entity (e.g., a base station), may transmit a counting request to a plurality of UEs on a broadcast channel. The counting request may identify the one or more MBMS services offered by the network. Accordingly, UEs interested in the MBMS service may respond to the counting request over a shared channel or a resource block. Upon receiving the counting response, the base station may estimate the number of interested UEs by measuring the received power-related characteristic of a channel over which the at least one counting response is received

Description

PHYSICAL LAYER COUNTING AND BEARER TYPE SELECTION

BACKGROUND

Field

The present disclosure relates generally to communication systems, and more particularly, to physical layer counting of user equipments (UEs) interested in one or more services of multimedia broadcast multicast service (MBMS) , and selecting a bearer based on the physical layer counting.

Background

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power) . Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is Long Term Evolution (LTE) . LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP) . LTE is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using OFDMA on the downlink (DL) , SC-FDMA on the uplink (UL) , and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE technology.

One example of increased demand is in the area of multimedia broadcast and multicast service (MBMS) that leverages capabilities of the wireless communication systems to offer streaming and download services (e.g., live TV, audio podcast, etc. ) to users on a mobile device. However, the increasing popularity of mobile TV and similar services lead to situations in which many users may want to watch or subscribe to the same content at the same time. In such instances, accurately identifying the number of users interested in the broadcast service may be helpful in preventing degradation of the wireless network. Conventional methods of identifying the number of users interested in MBMS services using radio resource control (RRC) counting or application layer counting may use valuable network resources, as they may induce high signaling load, and/or may be unreliable, as they may fail to count users that may be in an idle mode.

SUMMARY

The described features generally relate to one or more improved systems, methods, and/or devices for physical layer counting of UEs interested in one or more MBMS services, and selecting a bearer based on the physical layer counting. In some examples of the present disclosure, a network entity (e.g., a base station) , may transmit a counting request to one or more UEs on a broadcast channel. The counting request may identify the one or more MBMS services offered by the network. Accordingly, UEs interested in the MBMS service may respond to the counting request over a shared channel or a resource block. Based on the received messages from the interested UEs, the network entity may estimate the number of interested UEs by measuring a received power-related characteristics of a channel over which the counting messages are received. Additionally or alternatively, the network entity may select a bearer (i.e., broadcast, unicast or multicast bearer) based on the estimated number of UEs. In some aspects, the features of the present disclosure provide improvement over the conventional methods by reducing signaling load and more accurately counting active and idle UEs interested in the MBMS service.

According to a first set of illustrative embodiments, a method for wireless communication is described. The method may include transmitting, from a base station, a counting request to one or more UEs. The counting request may relate to one or more services of MBMS. The method may further comprise receiving, in response to the counting request, at least one counting response from the one or more UEs indicating interest in at least one of the one or more services. Based on the received counting response, the method may include determining a measurement of a received power- related characteristics of a channel over which the at least one counting response is received and determining an estimation of a number or a range of numbers of UEs interested in the at least one of the one or more services based on the measurement.

According to a second set of illustrative embodiments, an apparatus for wireless communication is described. The apparatus may comprise means for transmitting, from a base station, a counting request to one or more UEs. The counting request may relate to one or more services of MBMS. In some examples, the apparatus may further include means for receiving, in response to the counting request, at least one counting response from the one or more UEs indicating interest in at least one of the one or more services. The apparatus may further include means for determining a measurement of a received power-related characteristic of a channel over which the at least one counting response is received and means for determining an estimation of a number or a range of numbers of UEs interested in the at least one of the one or more services.

According to a third set of illustrative embodiments, a computer readable medium storing computer executable code for wireless communication is disclosed. The computer readable medium may comprise code for transmitting, from a base station, a counting request to one or more UEs. The counting request may relate to one or more services of MBMS. In some examples, the computer readable medium may further include code for receiving, in response to the counting request, at least one counting response from the one or more UEs indicating interest in at least one of the one or more services. The computer readable medium may further include code for determining a measurement of a received power-related characteristic of a channel over which the at least one counting response is received and code for determining an estimation of a number or a range of numbers of UEs interested in the at least one of the one or more services.

According to a fourth set of illustrative embodiments, yet another apparatus for wireless communication is disclosed. The apparatus may comprise a processor and a memory in electronic communication with the processor. The apparatus may further include instructions stored in the memory executable by the processor to transmit, from a base station, a counting request to one or more UEs. The counting request may relate to one or more services of MBMS. In some examples, the instructions may further be executable by the processor to receive, in response to the counting request, at least one counting response from the one or more UEs indicating interest in at least one of the one or more services. The instructions may further be executable by the processor to determine a measurement of a received power-related characteristic of a channel over which the at least one counting response is received and determine an estimation of a number or a range of numbers of UEs interested in the at least one of the one or more services.

According to a fifth set of illustrative embodiments, a method for wireless communication is disclosed. The method comprises receiving, at a UE, a counting request from a base station. The counting request may relate to one or more services of MBMS. The method may further determine whether to respond to the counting request and transmit, in response to the counting request, at least one counting response indicating interest in at least one of the one or more services based on the determination that a response is to be sent.

According to a sixth set of illustrative embodiments, an apparatus for wireless communication is disclosed. The apparatus may comprise means for receiving, at a UE, a counting request from a base station. The counting request may relate to one or more services of MBMS. The apparatus may further include means for determining whether to respond to the counting request and means for transmitting, in response to the counting request, at least one counting response indicating interest in at least one of the one or more services based on the determination that a response is to be sent.

According to a seventh set of illustrative embodiments, a computer readable medium storing computer executable code for wireless communication is disclosed. The computer readable medium may include code for receiving, at a UE, a counting request from a base station. The counting request may relate to one or more services of MBMS. The computer readable medium may further include code for determining whether to respond to the counting request and code for transmitting, in response to the counting request, at least one counting response indicating interest in at least one of the one or more services based on the determination that a response is to be sent.

According to an eight set of illustrative embodiments, an apparatus for wireless communication is disclosed. The apparatus may comprise a processor and a memory in electronic communication with the processor. The apparatus may further include instructions stored in the memory executable by the processor to receive, at a UE, a counting request from a base station. The counting request may relate to one or more services of MBMS. In some examples, the apparatus may further determine whether to respond to the counting request and transmit, in response to the counting request, at least one counting response indicating interest in at least one of the one or more services based on the determination that a response is to be sent.

The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of 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 connection with the accompanying figures. Each of the figures is provided for the purpose of illustration and description, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram conceptually illustrating an example of a telecommunications system, in accordance with an aspect of the present disclosure.

FIG. 2 is a block diagram illustrating an example of LTE network architecture.

FIG. 3 is a diagram illustrating an example an example of an access network.

FIG. 4 is a diagram illustrating an example of a DL frame structure in LTE.

FIG. 5 is a diagram illustrating an example of an UL frame structure in LTE.

FIG. 6 is a diagram illustrating an example of an evolved Node B and user equipment in an access network.

FIG. 7A is an example of an evolved MBMS (eMBMS) channel configuration in an MBSFN.

FIG. 7B is an example illustrating the format of an MSI MAC control element.

FIG. 8 is a diagram illustrating an example of a wireless communication system that facilitates physical layer counting and bearer selection.

FIG. 9 is a flow chart of a method of facilitating physical layer counting and bearer selection in accordance with the present disclosure.

FIG. 10 is a block diagram illustrating an example of a wireless communication system that facilitates physical layer counting and bearer selection.

FIG. 11 is a flow chart of a method of facilitating physical layer counting and bearer selection in accordance with the present disclosure.

FIG. 12 is a conceptual data flow diagram illustrating the data flow between different modules/means/components in an exemplary apparatus.

FIG. 13 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

FIG. 14 is a block diagram illustrating an example of a wireless communication system that facilitates physical layer counting and bearer selection.

FIG. 15 is a flow chart of a method of facilitating physical layer counting and bearer selection in accordance with the present disclosure.

FIG. 16 is a conceptual data flow diagram illustrating the data flow between different modules/means/components in an exemplary apparatus.

FIG. 17 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

As discussed above, accurately determining the number of UEs interested in MBMS service and optimally selecting an appropriate transmission bearer may be helpful in maximizing the limited resources of a wireless communication system. For instance, if a limited number of UEs (for example, but not limited to, less than four UEs) express interest in subscribing to MBMS services, it may be undesirable to establish a broadcast or multicast bearer. Alternatively, if a large number of UEs (for example, but not limited to, greater than ten UEs) express interest in MBMS services, selecting a unicast bearer may waste critical resources by increasing signaling load on the network. Therefore, accurately counting the number of UEs interested in MBMS service may alleviate misappropriation of network resources.

In some aspects, RRC counting or application layer counting may be utilized to identify the number UEs interested in an MBMS service. However, each of the RRC counting and the application layer counting methods suffer from drawbacks related to accuracy and signaling load.

For example, in RRC counting mechanism, UEs in RRC idle mode interested in the MBMS service may not respond to the counting request from the network entity. Therefore, in some examples, the network entity may count only active UEs interested in the MBMS service based on the RRC counting mechanism.

Alternatively, for example, an application layer counting method, while allowing RRC idle mode UEs to respond to the counting request, may suffer from drawbacks related to signaling load. For example, counting response messages in an application layer counting may be transmitted to broadcast/multicast service centre (BM-SC) via a unicast message, and therefore may increase the signal load on the wireless communication system. Moreover, in an application layer counting method, UEs in RRC idle mode may need to establish RRC connection prior to transmitting the counting response.

As a result, neither the RRC counting method nor the application layer counting method may provide counting accuracy without raising signaling load on the wireless network.

The present disclosure presents methods and apparatuses for utilizing physical layer counting to improve the counting accuracy and reduce signaling load. In accordance with the present disclosure, a network may transmit a counting request, including a list of one or more temporary mobile group identities (TMGIs) , to a plurality of UEs in the network over a broadcast channel. The counting request may identify one or more MBMS available services offered by the network. In response, UEs interested in the MBMS services based on the list of one or more TMGIs may respond to the counting request over a shared channel or resource block. In some examples, the base station may estimate the number of interested UEs by measuring a received power-related characteristic, such as but not limited to the received power or power spectrum property, of the channel over which the messages are received. Based on the estimated number of UEs or number range of UEs, a network entity may select a bearer for providing at least one of the one or more MBMS services. In some examples, the bearer may be selected from a group comprising a MBMS broadcast bearer, or a Single Cell Point-To-Multipoint (SC-PTM) bearer, or a unicast bearer.

FIG. 1 illustrates an example of a wireless communications system 100 in accordance with various aspects of the disclosure. The wireless communications system 100 includes base stations 105, UEs 115, and a core network 130. In some examples, one or more UEs 115 may include MBMS service module 805 configured to receive counting request messages from a base station 105 and determine whether to subscribe to at least one MBMS service. In some examples, MBMS service module 805 may be configured to generate a counting response message to be transmitted on a shared channel or resource block. Additionally or alternatively, one or more base station 105 may include a communication management module 810 configured to generate counting request messages and estimate the number of UEs or number range of UEs interested in at least one MBMS service and select a bearer for delivering the at least one MBMS service based on the estimate. The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The base stations 105 interface with the core network 130 through backhaul links 132 (e.g., S1, etc. ) and may perform radio configuration and scheduling for communication with the UEs 115, or may operate under the control of a base station controller (not shown) . In various examples, the base stations 105 may communicate, either directly or indirectly (e.g., through core network 130) , with each other over backhaul links 134 (e.g., X1, etc. ) , which may be wired or wireless communication links.

The base stations 105 may wirelessly communicate with the UEs 115 via one or more base station antennas. Each of the base station 105 sites may provide communication coverage for a respective geographic coverage area 110. In some examples, 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) , Home NodeB, a Home eNodeB, or some other suitable terminology. The geographic coverage area 110 for a base station 105 may be divided into sectors making up only a portion of the coverage area (not shown) . The wireless communications system 100 may include base stations 105 of different types (e.g., macro and/or small cell base stations) . There may be overlapping geographic coverage areas 110 for different technologies.

In some examples, the wireless communications system 100 is an LTE/LTE-Anetwork. In LTE/LTE-Anetworks, the term evolved Node B (eNB) may be generally used to describe the base stations 105, while the term UE may be generally used to describe the UEs 115. The wireless communications system 100 may be a Heterogeneous LTE/LTE-A network in which different types of eNBs provide coverage for various geographical regions. For example, each eNB or base station 105 may provide communication coverage for a macro cell, a small cell, and/or other types of cell. 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 base station, depending on context.

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 lower-powered base station, as compared with a macro cell, that may operate in the same or different (e.g., licensed, unlicensed, etc. ) frequency bands as macro cells. Small cells may include pico cells, femto cells, and micro cells according to various examples. A pico cell may cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell also may cover a relatively small geographic area (e.g., a home) 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 home, and the like) . An eNB for a macro cell may 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 home eNB. An eNB may support one or multiple (e.g.， two, three, four, and the like) cells (e.g., component carriers) .

The wireless communications system 100 may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

The communication networks that may accommodate some of the various disclosed examples may be packet-based networks that operate according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may 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 the base stations 105 or core network 130 supporting radio bearers for the user plane data. At the Physical (PHY) layer, the transport channels may be mapped to Physical channels.

The UEs 115 are 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 communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. A UE 115 may be a cellular phone, a smart phone, a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or the like. A UE may be able to communicate with various types of base stations and network equipment including macro eNBs, small cell eNBs, relay base stations, and the like.

In accordance with the present disclosure, a base station 105 or network entity (i.e., core network 130) may transmit to one or more UEs 115 system information, e.g., in a system information block (SIB) that includes random access parameters associated with a counting request. In some examples, the random access parameters may include a physical random access channel (PRACH) configuration index, a preamble index list, a PRACH mask index list, and/or preamble initial received target power. In some aspects, the preamble index list may identify the reserved random access preamble for the counting response. For example, when multiple TMGIs, each identifying one of a plurality of MBMS services, are included in a counting request, different random access preambles may be used to indicate different TMGIs that the UE 115 is interested in. In some examples, multiple TMGIs may be mapped to a plurality of random access preambles identified in the system information. Therefore, in some examples, a UE 115 may associate the first TMGI in the counting request list with a first random access preamble provided in the SIB. Similarly, a UE 115, interested in the second TMGI in the counting request, may respond to the counting request with a second random access preamble provided in the SIB. As a result, a base station 105 may identify number of UEs 115 interested in different MBMS services based on the correlation detection of the TMGI list with the random access preamble utilized by the UE 115 in the response.

In some examples, a UE 115 may be interested in a plurality of MBMS services. As a result, a UE 115 may respond to the counting request with a counting response message comprising a plurality of random access preambles. In one example, the counting response message may comprise a first random access preamble and a second random access preamble corresponding to the first TMGI and the second TMGI, respectively. The base station 105 may identify UE’s 115 interest in a plurality of MBMS services by performing correlation calculation on the received sequence of the counting response message with each preamble sequence. In some examples, the correlation calculations may be performed utilizing a Zadoff Chu sequence. Thus, in the example discussed above, the base station 105 may first perform correlation calculation for the first TMGI by detecting power characteristics of the first random access preamble in the received counting response message to estimate the number or range of number of UEs interested in the first TMGI. Additionally or alternatively, the base station 105 may perform a second correlation calculation for the second TMGI by detecting the power characteristics of the second random access preamble in the received sequence to estimate the number or range of number of UEs interested in the second TMGI.

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

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

Wireless communications system 100 may support operation on multiple cells or carriers, a feature which may be referred to as carrier aggregation (CA) or multi-carrier operation. A carrier may 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 herein. A UE 115 may be configured with multiple downlink CCs and one or more uplink CCs for carrier aggregation. Carrier aggregation may be used with both FDD and TDD component carriers.

In some examples of the present disclosure, a base station 105, following transmission of system information as discussed above, may transmit a counting request to one or more UEs 115 via multicast channel (MCCH) or physical downlink control channel (PDCCH) . UEs 115 may respond to the counting request with a message comprising a random access preamble on a shared physical random access channel (PRACH) . As illustrated in FIG. 1, different UEs 115 may be in different locations of a cell 110. As a result, one or more UEs 115 may utilize open loop power control to transmit the random access preamble to the base station 105 using parameters identified in the SIB, so that the received power from different UEs 115 may be similar.

In some examples, a base station 105, upon detecting at least one message comprising a random access preamble, may estimate a timing advance (TA) of UEs 115 by detecting the power peak of the correlation. Because different UEs 115 may have different timing advances (TAs) , the base station 105 may detect multiple power peaks on the PRACH, wherein each power peak may correspond to a different TA. As a result, a base station 105 may estimate the number of UEs 115 indicating an interest in MBMS service based on measuring power of each peak detected on the PRACH. Additionally or alternatively, counting responses of UEs 115 with same TA may be detected based on formation of a single power peak. Therefore, based on the magnitude of the measured power peaks, the base station 105 may be configured to determine the number of UEs that have expressed interest in MBMS service. In some examples, a network entity (i.e., base station 105 or core network 130) may select a bearer for providing the at least one of the one or more MBMS services based on the estimation.

FIG. 2 is a diagram illustrating LTE network architecture 200. The LTE network architecture 200 may be referred to as an Evolved Packet System (EPS) 200. The EPS 200 may include one or more user equipment (UE) 105, an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) 204, an Evolved Packet Core (EPC) 210, and an Operator’s Internet Protocol (IP) Services 222. The EPS can interconnect with other access networks, but for simplicity those entities/interfaces are not shown. As shown, the EPS provides packet-switched services, however, as those skilled in the art will readily appreciate, the various concepts presented throughout this disclosure may be extended to networks providing circuit-switched services.

The E-UTRAN includes the evolved Node B (eNB) 105, and may include a Multicast Coordination Entity (MCE) 228. In some aspects, eNB 105 and UE 115 may be examples of base station 105 and UEs 115 illustrated with reference to FIG. 1. The eNBs 105 provides user and control planes protocol terminations toward the UEs 105. The eNB 105 may be connected to the other eNBs 105 via a backhaul (e.g., an X2 interface) . The MCE 228 allocates time/frequency radio resources for evolved Multimedia Broadcast Multicast Service (MBMS) (eMBMS) , and determines the radio configuration (e.g., a modulation and coding scheme (MCS) ) for the eMBMS. The MCE 228 may be a separate entity or part of the eNB 105. The eNB 105 may also be referred to as a base station, a Node B, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , or some other suitable terminology. The eNB 105 provides an access point to the EPC 210 for one or more UEs 115.

In some examples of the present disclosure, one or more UEs 115 may include a MBMS service module 805 configured to receive counting request messages from eNBs 105. In some examples, the MBMS service module 805 may determine whether to subscribe to one or more MBMS services. Based in part on the determination, the MBMS service module 805 may generate a response message comprising a random access preamble on the shared PRACH. In some examples, the response message may be generated based on random access parameters received from eNB 105 in system information block (e.g., SIB13 for LTE) . The random access parameters may include a preamble index list corresponding with the TMGI list included in the counting request. Therefore, in some aspects, the UE 115 may subscribe to one or more MBMS services by correlating the random access preamble in the SIB with the TMGI list received in the counting request, and transmitting the response message with the correlated random access preamble to indicate interest in the corresponding MBMS service.

As discussed above, a UE 115 may be interested in a plurality of MBMS services. As a result, a UE 115 may respond to the counting request with a counting response message comprising a plurality of random access preambles. In one example, the counting response message may comprise a first random access preamble and a second random access preamble corresponding to the first TMGI and the second TMGI, respectively. The base station 105 may identify UE’s 115 interest in a plurality of MBMS services by performing correlation calculation on the received sequence of the counting response message with each preamble sequence. In some examples, the correlation calculations may be performed utilizing a Zadoff Chu sequence. Thus, in the example discussed above, the base station 105 may first perform correlation calculation for the first TMGI by detecting power characteristics of the first random access preamble in the received counting response message to estimate the number or range of number of UEs interested in the first TMGI. Subsequently, the eNBs 105 may perform a second correlation calculation for the second TMGI by detecting the power characteristics of the second random access preamble in the received sequence to estimate the number or range of number of UEs interested in the second TMGI.

Additionally or alternatively, E-UTRAN 204 may include a communication management module 810. The communication management module 810 may be part of the eNB 105 or MCE 228. In some examples of the present disclosure, the communication management module 810 may be configured to generate counting request, including a TMGI list for MBMS services, where each MBMS service is associated with a unique TMGI on the TMGI list. The counting request may be transmitted to one or more UEs 115 on a broadcast channel. UEs 115 interested in the TMGI (s) may respond to the counting request on a shared channel or resource block with a counting response message. In some examples, the communication management module 810 may be configured to estimate the number or number range of interested UEs based on the measurement of a received power-related characteristic of a channel over which the at least one or more counting response message (s) are received.

The eNB 105 may be connected to the EPC 210. The EPC 210 may include a Mobility Management Entity (MME) 212, other MMEs 214, a Serving Gateway 216, a Multimedia Broadcast Multicast Service (MBMS) Gateway 224, a Broadcast Multicast Service Center (BM-SC) 226, and a Packet Data Network (PDN) Gateway 218. The MME 212 is the control node that processes the signaling between the UE 105 and the EPC 210. Generally, the MME 212 provides bearer and connection management. All user IP packets are transferred through the Serving Gateway 216, which itself is connected to the PDN Gateway 218. The PDN Gateway 218 provides UE IP address allocation as well as other functions. The PDN Gateway 218 and the BM-SC 226 are connected to the IP Services 222. The IP Services 222 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service (PSS) , and/or other IP services. The BM-SC 226 may provide functions for MBMS user service provisioning and delivery. The BM-SC 226 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a PLMN, and may be used to schedule and deliver MBMS transmissions. The MBMS Gateway 224 may be used to distribute MBMS traffic to the eNBs 105 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

FIG. 3 is a diagram illustrating an example of an access network 300 in an LTE network architecture. In this example, the access network 300 is divided into a number of cellular regions (cells) 302. One or more lower power class eNBs 308 may have cellular regions 310 that overlap with one or more of the cells 302. The lower power class eNB 308 may be a femto cell (e.g., home eNB (HeNB) ) , pico cell, micro cell, or remote radio head (RRH) . The macro eNBs 304 are each assigned to a respective cell 302 and are configured to provide an access point to the EPC 210 for all the UEs 306 in the cells 302. There is no centralized controller in this example of an access network 300, but a centralized controller may be used in alternative configurations. The eNBs 304 are responsible for all radio related functions including radio bearer control, admission control, mobility control, scheduling, security, and connectivity to the serving gateway 116. An eNB may support one or multiple (e.g., three) cells (also referred to as a sectors) .

The modulation and multiple access scheme employed by the access network 200 may vary depending on the particular telecommunications standard being deployed. In LTE applications, OFDM is used on the DL and SC-FDMA is used on the UL to support both frequency division duplex (FDD) and time division duplex (TDD) . As those skilled in the art will readily appreciate from the detailed description to follow, the various concepts presented herein are well suited for LTE applications. However, these concepts may be readily extended to other telecommunication standards employing other modulation and multiple access techniques. By way of example, these concepts may be extended to Evolution-Data Optimized (EV-DO) or Ultra Mobile Broadband (UMB) . EV-DO and UMB are air interface standards promulgated by the 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 family of standards and employs CDMA to provide broadband Internet access to mobile stations. These concepts may also be extended to Universal Terrestrial Radio Access (UTRA) employing Wideband-CDMA (W-CDMA) and other variants of CDMA, such as TD-SCDMA； Global System for Mobile Communications (GSM) employing TDMA； and Evolved UTRA (E-UTRA) , IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, and Flash-OFDM employing OFDMA. UTRA, E-UTRA, UMTS, LTE and GSM are described in documents from the 3GPP organization. CDMA2000 and UMB are described in documents from the 3GPP2 organization. The actual wireless communication standard and the multiple access technology employed will depend on the specific application and the overall design constraints imposed on the system.

The eNBs 304 may have multiple antennas supporting MIMO technology. The use of MIMO technology enables the eNBs 304 to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing may be used to transmit different streams of data simultaneously on the same frequency. The data streams may be transmitted to a single UE 306 to increase the data rate or to multiple UEs 306 to increase the overall system capacity. This is achieved by spatially precoding each data stream (i.e., applying a scaling of amplitude and a phase) and then transmitting each spatially precoded stream through multiple transmit antennas on the DL. The spatially precoded data streams arrive at the UE (s) 306 with different spatial signatures, which enables each of the UE (s) 306 to recover the one or more data streams destined for that UE 306. On the UL, each UE 306 transmits a spatially precoded data stream, which enables the eNB 304 to identify the source of each spatially precoded data stream.

Spatial multiplexing is generally used when channel conditions are good. When channel conditions are less favorable, beamforming may be used to focus the transmission energy in one or more directions. This may be achieved by spatially precoding the data for transmission through multiple antennas. To achieve good coverage at the edges of the cell, a single stream beamforming transmission may be used in combination with transmit diversity.

In the detailed description that follows, various aspects of an access network will be described with reference to a MIMO system supporting OFDM on the DL. OFDM is a spread-spectrum technique that modulates data over a number of subcarriers within an OFDM symbol. The subcarriers are spaced apart at precise frequencies. The spacing provides “orthogonality” that enables a receiver to recover the data from the subcarriers. In the time domain, a guard interval (e.g., cyclic prefix) may be added to each OFDM symbol to combat inter-OFDM-symbol interference. The UL may use SC-FDMA in the form of a DFT-spread OFDM signal to compensate for high peak-to-average power ratio (PAPR) .

FIG. 4 is a diagram 400 illustrating an example of a DL frame structure in LTE. A frame (10 ms) may be divided into 10 equally sized subframes. Each subframe may include two consecutive time slots. A resource grid may be used to represent two time slots, each time slot including a resource block. The resource grid is divided into multiple resource elements. In LTE, for a normal cyclic prefix, a resource block contains 12 consecutive subcarriers in the frequency domain and 7 consecutive OFDM symbols in the time domain, for a total of 84 resource elements. For an extended cyclic prefix, a resource block contains 12 consecutive subcarriers in the frequency domain and 6 consecutive OFDM symbols in the time domain, for a total of 72 resource elements. Some of the resource elements, indicated as

R

402, 404, include DL reference signals (DL-RS) . The DL-RS include Cell-specific RS (CRS) (also sometimes called common RS) 402 and UE-specific RS (UE-RS) 404. UE-RS 404 is transmitted on the resource blocks upon which the corresponding physical DL shared channel (PDSCH) is mapped. The number of bits carried by each resource element depends on the modulation scheme. Thus, the more resource blocks that a UE receives and the higher the modulation scheme, the higher the data rate for the UE.

FIG. 5 is a diagram 500 illustrating an example of an UL frame structure in LTE. The available resource blocks for the UL may be partitioned into a data section and a control section. The control section may be formed at the two edges of the system bandwidth and may have a configurable size. The resource blocks in the control section may be assigned to UEs for transmission of control information. The data section may include all resource blocks not included in the control section. The UL frame structure results in the data section including contiguous subcarriers, which may allow a single UE to be assigned all of the contiguous subcarriers in the data section.

A UE may be assigned

resource blocks

510a, 510b in the control section to transmit control information to an eNB. The UE may also be assigned resource blocks 520a, 520b in the data section to transmit data to the eNB. The UE may transmit control information in a physical UL control channel (PUCCH) on the assigned resource blocks in the control section. The UE may transmit data or both data and control information in a physical UL shared channel (PUSCH) on the assigned resource blocks in the data section. A UL transmission may span both slots of a subframe and may hop across frequency.

A set of resource blocks may be used to perform initial system access and achieve UL synchronization in a physical random access channel (PRACH) 530. The PRACH 530 carries a random sequence and cannot carry any UL data/signaling. Each random access preamble occupies a bandwidth corresponding to six consecutive resource blocks. The starting frequency is specified by the network. That is, the transmission of the random access preamble is restricted to certain time and frequency resources. There is no frequency hopping for the PRACH. The PRACH attempt is carried in a single subframe (1 ms) or in a sequence of few contiguous subframes and a UE can make a single PRACH attempt per frame (10 ms) .

FIG. 6 is a block diagram of an eNB 610 in communication with a UE 650 in an access network. In the DL, upper layer packets from the core network are provided to a controller/processor 675. The controller/processor 675 implements the functionality of the L2 layer. In the DL, the controller/processor 675 provides header compression, ciphering, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocations to the UE 650 based on various priority metrics. The controller/processor 675 is also responsible for HARQ operations, retransmission of lost packets, and signaling to the UE 650.

The transmit (TX) processor 616 implements various signal processing functions for the L1 layer (i.e., physical layer) . The signal processing functions include coding and interleaving to facilitate forward error correction (FEC) at the UE 650 and mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK) , quadrature phase-shift keying (QPSK) , M-phase-shift keying (M-PSK) , M-quadrature amplitude modulation (M-QAM) ) . The coded and modulated symbols are then split into parallel streams. Each stream is then mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 674 may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 650. Each spatial stream may then be provided to a different antenna 620 via a separate transmitter 618TX. Each transmitter 618TX may modulate an RF carrier with a respective spatial stream for transmission. In addition, eNB 610 may include a communication management module 810 configured for physical layer counting and selecting a bearer based on the estimation.

At the UE 650, each receiver 654RX receives a signal through its respective antenna 652. Each receiver 654RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 656. The RX processor 656 implements various signal processing functions of the L1 layer. The RX processor 656 may perform spatial processing on the information to recover any spatial streams destined for the UE 650. If multiple spatial streams are destined for the UE 650, they may be combined by the RX processor 656 into a single OFDM symbol stream. The RX processor 656 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT) . The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the eNB 610. These soft decisions may be based on channel estimates computed by the channel estimator 658. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the eNB 610 on the physical channel. The data and control signals are then provided to the controller/processor 659.

The controller/processor 659 implements the L2 layer. The controller/processor can be associated with a memory 660 that stores program codes and data. The memory 660 may be referred to as a computer-readable medium. In the UL, the controller/processor 659 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer packets from the core network. The upper layer packets are then provided to a data sink 662, which represents all the protocol layers above the L2 layer. Various control signals may also be provided to the data sink 662 for L3 processing. The controller/processor 659 is also responsible for error detection using an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support HARQ operations. In addition, UE 650 may include MBMS service module 805 configured to determine whether to subscribe to MBMS services and responding to a counting request message with a counting response message comprising a random access preamble on a shared channel or resource block.

In the UL, a data source 667 is used to provide upper layer packets to the controller/processor 659. The data source 667 represents all protocol layers above the L2 layer. Similar to the functionality described in connection with the DL transmission by the eNB 610, the controller/processor 659 implements the L2 layer for the user plane and the control plane by providing header compression, ciphering, packet segmentation and reordering, and multiplexing between logical and transport channels based on radio resource allocations by the eNB 610. The controller/processor 659 is also responsible for HARQ operations, retransmission of lost packets, and signaling to the eNB 610.

Channel estimates derived by a channel estimator 658 from a reference signal or feedback transmitted by the eNB 610 may be used by the TX processor 668 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 668 may be provided to different antenna 652 via separate transmitters 654TX. Each transmitter 654TX may modulate an RF carrier with a respective spatial stream for transmission.

The UL transmission is processed at the eNB 610 in a manner similar to that described in connection with the receiver function at the UE 650. Each receiver 618RX receives a signal through its respective antenna 620. Each receiver 618RX recovers information modulated onto an RF carrier and provides the information to a RX processor 670. The RX processor 670 may implement the L1 layer.

The controller/processor 675 implements the L2 layer. The controller/processor 675 can be associated with a memory 676 that stores program codes and data. The memory 676 may be referred to as a computer-readable medium. In the UL, the controller/processor 675 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer packets from the UE 650. Upper layer packets from the controller/processor 675 may be provided to the core network. The controller/processor 675 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

FIG. 7A is a diagram 750 illustrating an example of an evolved MBMS (eMBMS) channel configuration in an MBSFN. The eNBs 752 in cells 752' may form a first MBSFN area and the eNBs 754 in cells 754'may form a second MBSFN area. The

eNBs

752, 754 may each be associated with other MBSFN areas, for example, up to a total of eight MBSFN areas. A cell within an MBSFN area may be designated a reserved cell. Reserved cells do not provide multicast/broadcast content, but are time-synchronized to the cells 752', 754' and may have restricted power on MBSFN resources in order to limit interference to the MBSFN areas. Each eNB in an MBSFN area synchronously transmits the same eMBMS control information and data. Each area may support broadcast, multicast, and unicast services. A unicast service is a service intended for a specific user, e.g., a voice call. A multicast service is a service that may be received by a group of users, e.g., a subscription video service. A broadcast service is a service that may be received by all users, e.g., a news broadcast. Referring to FIG. 7A, the first MBSFN area may support a first eMBMS broadcast service, such as by providing a particular news broadcast to UE 770. The second MBSFN area may support a second eMBMS broadcast service, such as by providing a different news broadcast to UE 760. Each MBSFN area supports one or more physical multicast channels (PMCH) (e.g., 15 PMCHs) . Each PMCH corresponds to a multicast channel (MCH) . Each MCH can multiplex a plurality (e.g., 29) of multicast logical channels. Each MBSFN area may have one multicast control channel (MCCH) . As such, one MCH may multiplex one MCCH and a plurality of multicast traffic channels (MTCHs) and the remaining MCHs may multiplex a plurality of MTCHs.

A UE can camp on an LTE cell to discover the availability of eMBMS service access and a corresponding access stratum configuration. Initially, the UE may acquire a system information block (SIB) 13 (SIB13) . Subsequently, based on the SIB13, the UE may acquire an MBSFN Area Configuration message on an MCCH. Subsequently, based on the MBSFN Area Configuration message, the UE may acquire an MCH scheduling information (MSI) MAC control element. The SIB13 may include (1) an MBSFN area identifier of each MBSFN area supported by the cell； (2) information for acquiring the MCCH such as an MCCH repetition period (e.g., 32, 64, …, 256 frames) , an MCCH offset (e.g., 0, 1, …, 10 frames) , an MCCH modification period (e.g., 512, 1024 frames) , a signaling modulation and coding scheme (MCS) , subframe allocation information indicating which subframes of the radio frame as indicated by repetition period and offset can transmit MCCH； and (3) an MCCH change notification configuration. There is one MBSFN Area Configuration message for each MBSFN area. The MBSFN Area Configuration message may indicate (1) a temporary mobile group identity (TMGI) and an optional session identifier of each MTCH identified by a logical channel identifier within the PMCH, and (2) allocated resources (e.g., radio frames and subframes) for transmitting each PMCH of the MBSFN area and the allocation period (e.g., 4, 8, …, 256 frames) of the allocated resources for all the PMCHs in the area, and (3) an MCH scheduling period (MSP) (e.g., 8, 16, 32, …, or 1024 radio frames) over which the MSI MAC control element is transmitted.

FIG. 7B is a diagram 790 illustrating the format of an MSI MAC control element. The MSI MAC control element may be sent once each MSP. The MSI MAC control element may be sent in the first subframe of each scheduling period of the PMCH. The MSI MAC control element can indicate the stop frame and subframe of each MTCH within the PMCH. There may be one MSI per PMCH per MBSFN area.

Referring to FIG. 8, a wireless communication system 800 is illustrated that facilitates physical layer counting and bearer selection. For example, system 800 includes a UE 115 that may communicate with a network entity 806 via one or more over-the-air links, such as one or more uplinks (ULs) 802 and/or one or more downlinks (DLs) 804. In some examples, the network entity 806 may be an aspect of a base station 105 or core network 130 illustrated with reference to FIG. 1.

In some examples, network entity 806 may include one or more types of network components, for example, an access point, including a base station (BS) , Node B, eNode, a femto cell, a relay, a peer-to-peer device, an authentication, authorization and accounting (AAA) server, a mobile switching center (MSC) , or a radio network controller (RNC) , etc., that may enable UE 105 to communicate and/or establish and maintain wireless communication links 802 and/or 804, which may include a communication session over a frequency or a band of frequencies that form a communication channel, to communicate with network entity 806. In an additional aspect, for example, base station network entity 806 may operate according to a radio access technology (RAT) standard, e.g., GSM, CDMA, W-CDMA, HSPA or a long term evolution (LTE) .

In some examples, a transceiver (not shown) of the network entity 806 may generate and transmit a counting request to one or more UE 115 via DL 804. In some examples, the counting request may be transmitted over a broadcast channel (e.g., MCCH or PDCCH) . The counting request may be related to one or more MBMS services provided by the network entity 806. In response, the MBMS service module 805 may determine whether the UE 115 is interested in at least one MBMS service specified in the counting request. In accordance with the present disclosure, the UE 115 may be in RRC idle mode or an RRC active mode. Based on the determination, the MBMS service module 805 may generate a counting response message comprising a random access preamble via UL 802. The selection of the random access preamble may be based on random access parameters previously transmitted by the network entity 806 in a SIB.

In one or more examples, the random access parameters may include, but are not limited to, one or more of a PRACH configuration index, a PRACH mask index list, a preamble initial received target power, or a preamble index list. In accordance with the present disclosure, the preamble index list may identify one, or a plurality of, random access preamble (s) for counting response message. For example, when multiple TMGIs are included in the counting request, multiple random access preambles may be used by the MBMS service module 805 to identify different TMGIs associated with MBMS services.

In one aspect, for example, MBMS service module 805 may associate a first TMGI in the counting request list with a first random access preamble provided in the SIB. Similarly, for example, MBMS service module 805, interested in a second TMGI in the counting request, may respond to the counting request with a second random access preamble provided in the SIB. As a result, UE 115 may respond with one or more counting response messages identifying one or more selected MBMS services based on one or more random access preambles selected from the SIB.

Upon receiving at least one counting response message from the UE 115, the power measurement component 815 may identify a number or a range of the number of UEs 115 interested in different MBMS services based on the correlation detection of the TMGI list with the random access preamble utilized by the UE 115 in the response. In some examples, the power measurement component 815 may determine a measurement of a received power-related characteristic of a channel over which the at least one counting response message is received. For instance, the power measurement component 815 may measure at least one or more power peaks on the PRACH associated with different TAs of different UEs 115. In some examples, the counting responses of UEs 115 with same TA may form a single peak. As a result, power measurement component 815 may determine the power-related characteristics of each peak to estimate the number of UEs that expressed interest in one or more MBMS services.

Additionally or alternatively, estimation component 820 may utilize the measurements of the power measurement component 815 to estimate the number or a range of the number of UEs interested in MBMS services. For example, the estimation component 820 may determine whether the measurement of the received power-related characteristics satisfies at least one target threshold. For example, in an aspect, the at least one target threshold may include an upper target threshold above which a number of UEs may be efficiently served by a broadcast carrier to deliver an MBMS service, and below which a multicast or unicast bearer may be utilized. Further, for example, in an alternative or additional aspect, the at least one target threshold may include a lower target threshold above which a number of UEs may be efficiently served by a multicast or unicast bearer to deliver an MBMS service, and/or below which no MBMS service may be provided due to lack of interest. In one implementation, which is listed here as an example but which should not be construed as limiting, the at least one target threshold may be -100dBM. In some instances, for example, if the received power on the PRACH is below the target threshold, such as the lower target threshold, the estimation component 820 may determine that either no UE or only a few UEs (e.g., four to ten UEs) are interested in at least one MBMS service. In contrast, if the received power on the PRACH is above the target threshold, such as the upper target threshold, the estimation component 820 may determine that a large number of UEs (e.g., greater than ten UEs) may be interested in at least one MBMS service.

As a result of the estimation, the bearer selection component 825 may select a bearer based on the number of UEs 115 that expressed interest in at least one MBMS service. For instance, if the received power on the PRACH is above a target threshold, the bearer selection component 825 may select a first bearer. Alternatively, if the received power on the PRACH is below the target threshold, the bearer selection component 825 may select second bearer. The first or second bearers may include MBMS broadcast bearer, SC-PTM bearer, or unicast bearer.

Additionally or alternatively, if the received power on the PRACH is below the target threshold, the network entity 806 may transmit a follow-up message to UE 115 requesting the MBMS service module 805 to respond again (e.g., a follow up response) to the initial counting request. Therefore, the bearer selection component 825 may select a bearer based on the power-related characteristic of a channel over which the follow up random access response message is received.

FIG. 9 illustrates an example of a diagram 900 for facilitating physical layer counting and bearer selection. Diagram 900 may include a UE 115, base station 105 and MCE 228 that may be an example of UE 115, base station 105, and the MCE 228 described with reference to FIGs. 1-2. In accordance with the present disclosure, the base station 105, at step 905, may transmit system information (e.g., SIB13 for LTE) with RACH configuration for counting to the UE 115. In some examples, the system information may include random access parameters, including PRACH configuration index, preamble index list, PRACH mask index list and preamble initial received target power. In some aspects, preamble index list may indicate the reserved random access preambles for a counting response. When multiple TMGIs associated with different MBMS services are received with a counting request, the UE 115 may utilize different random access preambles to identify different TMGIs, and therefore respond in a counting response with an appropriate random access preamble. Additionally or alternatively, the system information may include open loop power control parameters that may control the transmission of random access preamble. In the event that the system information fails to include open loop power control parameters, the UE 115 may utilize root sequence index of LTE SIB2 for transmitting random access preambles.

The MCE 228, at step 910, may transmit a counting request to the UE 115. In some examples, the counting request may be forwarded to the UE 115 via the base station 105. The counting request may relate to one or more MBMS services provided by the network entity. In some examples, the counting request may be transmitted via a broadcast channel (e.g., MCCH or PDCCH) . Upon receiving the counting request, the UE 115, at step 915, may determine whether to subscribe to at least one or more MBMS services. If the UE 115 determines to subscribe to one or more MBMS services, the UE 115, at step 920, may transmit a counting response message (s) to the base station 105. The counting response message (s) may comprise random access preambles transmitted utilizing open loop power control. The transmission power of the random access preambles may be based on open loop power control parameters received in the system information. In some examples, the random access preambles are transmitted on shared PRACH.

In some examples, the base station 105 may receive at least one counting response message from one or more UEs 115. Upon receiving the counting response messages, the base station 105, at step 925, may transmit a random access response to UE 115. Subsequently, the base station 105, at step 930, may measure the received power-related characteristics of a channel over which the at least one counting response is received. In some examples, the base station 105 may measure the power-related characteristics of the channel by detecting one or more power peaks on the PRACH, wherein each peak may correspond to the timing advance (TA) of UEs 115. In some examples, the base station 105 may be unable to determine the exact number of interested UEs. For instance, due to fast fading, measurement errors, or other transmission errors, the base station 105 may not detect power-related characteristics of every random access preamble. However, in such instances, the base station 105, at step 935, may determine the relevant range of UEs 115 interested in the MBMS services based on the measurements. For example, the base station 105, may determine that there are a large number of UEs (such as, but not limited to, greater than ten UEs) , a medium number of UEs (such as, but not limited to, between one to ten UEs) or no UEs interested in the MBMS services based on detection of the one or more power peaks.

In one or more examples, the base station 105 may estimate the relevant range of interested UEs 115 by determining whether the received power on the PRACH satisfies a target threshold. If the received power on the PRACH falls below the target threshold, the base station 105, in some instances, may request the UE 115 to retransmit the counting response messages to the base station 105 by transmitting a follow-up counting request message to the UE 115. As a result, the base station 105 may measure the power-related characteristics of the retransmitted counting response message to estimate the number or range of UEs interested in a MBMS service.

Upon determining the estimated the number or a range of number of UEs interested in MBMS, the base station 105, at step 940, may transmit a counting response message to MCE 228 that identifies the determined estimation. As a result, the MCE 228, at step 945, may select a bearer based on the estimated number or a range of number of UEs per cell. For example, if the estimated number or range of number of UEs per cell exceeds a threshold, the MCE 228 may, for example, select a broadcast bearer. In some examples, broadcast bearer may be selected when interested UEs are distributed in adjacent cells of MBSFN area. In other examples, the MCE 228 may select SC-PTM bearer or unicast bearer if the number of interested UEs is in disjointed cells. Alternatively, for example, if the number of interested UEs is relatively low (e.g., below four UEs) or falls below a threshold, the MCE 228 may select a unicast bearer to provide MBMS services.

FIG. 10 is a block diagram containing a plurality of sub-components of a communication management module 810 (see FIG. 8) , which may be implemented by a network entity (e.g., an eNodeB) when managing physical layer counting and bearer selection. Communication management module 810 may include a power management component 815, which may be configured to measure power-related characteristics of channels on which one or more counting responses may be received. In addition, the communication management module 810 may also include estimation component 820 for estimating the number or a range of number of UEs interested in MBMS services based on the measurement.

Additionally or alternatively, the communication management module 810 may include a bearer selection component 825 for selecting the optimal bearer based on the estimations. In yet further example, the communication management module 810 may include a SIB generation component 1005 for generating random access parameters, including open loop power control parameters for utilization by the UE. Furthermore, the communication management module 810 may include a count requesting component 1010 for generating a counting request or a follow-up counting request for transmission to the one or more UEs by a transceiver (not shown) . The communication management module 810 may also include a preamble identification component 1015 for generating a response preamble indicator identifying whether the one or more UEs should use a base station designated shared preamble or a randomly selected UE preamble.

FIG. 11 illustrates an example method 1100 of the present disclosure, which may comprise a method for physical layer counting and selecting optimal bearer in a wireless communication system. In an aspect, method 1100 may be performed by a network entity (e.g., an eNodeB) or a component of the network entity, such as, but not limited to, communication management module 810 of FIG. 8 and FIG. 10. In an aspect, at block 1102, method 1100 may optionally include transmitting system information from a base station to the one or more UEs. In an aspect, block 1102 may be performed by SIB generation component 1005 of FIG. 10.

In addition, method 1100 may include, at block 1104, transmitting a counting request to one or more UEs. The counting request may relate to one or more MBMS services. Aspects of block 1104 may be performed by communication management module 810 and/or count requesting component 1010 of FIG. 10 in the manner as described herein. Furthermore, method 1100 may include, at block 1106, receiving, in response to the counting request, a counting response message from the one or more UEs indicating an interest in at least one or more MBMS services. In some examples, block 1106 may be performed by communication management module 810 and/or a receiver (not shown) in the manner as described herein.

Moreover, method 1100 may include, at block 1108, determining a measurement of a received power-related characteristics of a channel over which the at least one counting response message is received. In some examples, the aspects of block 1108 may be performed by communication management module 810 and/or the power management component 815 of FIG. 10 in the manner described herein. The method 1100 may further, at block 1110, determine an estimation of a number or a range of numbers of UEs interested in the at least one of the one or more services based on the measurement. The aspects of block 1110 may be performed by communication management module 810 and/or estimation component 820 described with reference to FIG. 10. Additionally or alternatively, the method 1100 may also include block 1112 for selecting a bearer for providing the one or more services based in part on the estimation. Block 1112 may be performed by communication management module 810 and/or bearer selection component 825 described with reference to FIG. 10.

FIG. 12 is a conceptual data flow diagram 1200 illustrating the data flow between different modules/means/components in an exemplary apparatus 1202. The apparatus may be an eNodeB or a network entity (e.g., MCE) . The apparatus includes a receiving module 1204 that is configured to receive data (e.g., sent to apparatus 1202 by other network entities and/or UEs) and a transmission module 1205 that is configured to transmit at least physical layer counting requests to the one or more UEs 115.

The apparatus may include additional modules that perform each of the steps of the algorithm in the aforementioned flow chart of FIG. 9 and FIG. 11. As such, each step in the aforementioned flow charts of FIGS. 9 and 11 may be performed by a module and the apparatus may include one or more of those modules. The modules may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

In accordance with the present disclosure, the SIB generation component 1005 may optionally generate system information, including random access parameters and open loop power control parameters for utilization by the UE 115. The system information may be forwarded to the transmission module 1205 to be transmitted to the UE 115. The apparatus 1202 may also include preamble identification component 1015 configured to provide a preamble identifier to identify whether the one or more UEs 115 should use a base station designated shared preamble or a randomly selected UE preamble. The preamble identifier may be forwarded to the count requesting component 1010 to be attached to the count request. The count request may relate to one or more services of MBMS offered by the network. In some examples, the count requesting component 1010 may forward the generated count request to the transmission module 1205 for transmission to the UE 115 over a broadcast channel.

Upon receiving a count request from apparatus 1202, the UE 115 may transmit a counting response message indicating interest in at least one of the MBMS services. The count response message may be received by the receiving module 1204 and forwarded to the power management component 815. The power management component 815 may measure received power-related characteristics of a channel over which the at least one counting response message is received.

In some aspects, an estimation component 820 may estimate a number or a range of numbers of UEs interested in the at least one of the MBMS services based on the measurements performed by the power management component 815. In some examples, the estimation component 820 may forward the estimated number or range of number of UEs to bearer selection component 825. The bearer selection component 825 may be part of an eNB or MCE. Accordingly, the bearer selection component 825 may select a bearer based on the estimations.

FIG. 13 is a diagram 1300 illustrating an example of a hardware implementation for an apparatus employing a processing system 1314. The processing system 1314 may be implemented with a bus architecture, represented generally by the bus 1324. The bus 1324 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 1314 and the overall design constraints. The bus 1324 links together various circuits including one or more processors and/or hardware modules, represented by the processor 1304, the

modules

815, 820, 825, 1005, 1010, 1015, and the computer-readable medium /memory 1306. The bus 1324 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system 1314 may be coupled to a transceiver 1310. The transceiver 1310 is coupled to one or more antennas 1320. The transceiver 1310 provides a means for communicating with various other apparatus over a transmission medium. The transceiver 1310 receives a signal from the one or more antennas 1320, extracts information from the received signal, and provides the extracted information to the processing system 1314, specifically the reception module 1204 described with reference to FIG. 12. In addition, the transceiver 1310 receives information from the processing system 1314, specifically the transmission module 1205 described with reference to FIG. 12, and based on the received information, generates a signal to be applied to the one or more antennas 1320. The processing system 1314 includes a processor 1304 coupled to a computer-readable medium /memory 1306. The processor 1304 is responsible for general processing, including the execution of software stored on the computer-readable medium /memory 1306. The software, when executed by the processor 1304, causes the processing system 1314 to perform the various functions described supra for any particular apparatus. The computer-readable medium /memory 1306 may also be used for storing data that is manipulated by the processor 1304 when executing software. The processing system further includes at least one of the power management component 815, estimation component 820, bearer selection component 825, SIB generation component 1005, count requesting component 1010 and preamble identification component 1015. The modules may be software modules running in the processor 1304, resident/stored in the computer readable medium /memory 1306, one or more hardware modules coupled to the processor 1304, or some combination thereof. The processing system 1314 may be a component of the eNB 610 and may include the memory 676 and/or at least one of the TX processor 616, the RX processor 670, and the controller/processor 675.

FIG. 14 is a block diagram containing a plurality of sub-components of a MBMS service module 805 (see FIG. 8) , which may be implemented by a UE 115 when managing physical layer counting. MBMS service module 805 may include a random access parameter component 1405 for receiving and processing the system information received from the base station. The count request receiver component 1410 may process the received counting request messages associated with one or more MBMS services. MBMS service determination component 1415 may determine whether to respond to the counting request message. In some examples, based on the determination, the counting response generation component 1420 may generate a counting response message to express interest in at least one MBMS service. Functionalities of the MBMS service module 805 are described with reference to the method illustrated in FIG. 15.

FIG. 15 illustrates an example method 1500 of the present disclosure, which may comprise a method for physical layer counting and selecting optimal bearer in a wireless communication system. In an aspect, method 1500 may be performed by a UE or a component of the UE, such as, but not limited to, MBMS service module 805 of FIG. 8 and FIG. 14. In an aspect, at block 1502, method 1500 may optionally include receiving system information from a base station comprising random access parameters and open loop power control parameters. In an aspect, block 1502 may be performed by MBMS service module 805 and/or random access parameter 1405 of FIG. 14.

The method 1500, at block 1504, may further include receiving a counting request from a base station. The counting request may relate to one or more MBMS services provided by the network entity. In some examples, the aspects of block 1504 may be performed by MBMS service module 805 and/or count request receiver component 1410 described with reference to FIG. 14. The method 1500, at block 1506, may determine whether to respond to the counting request. The aspects of block 1506 may be performed by MBMS service module 805 and/or MBMS service determination component 13415 as described with reference to FIG. 14. Based on the determination to subscribe to at least one MBMS service, the method 1500, at block 1508, may transmit a counting response message on a shared channel indicating an interest in at least one MBMS service. The aspects of block 1508 may be performed by MBMS service module 805 and/or counting response generation component 1420 as described with reference to FIG. 14.

Additionally or alternatively, the method 1500, at block 1510, may optionally include receiving a follow-up counting request from the base station requesting the UE to retransmit the at least one counting response. The aspects of block 1510 may be performed by MBMS service module 805 and/or count request receiver component 1410 as described with reference to FIG. 14. In some examples, the UE, at block 1512 may retransmit the at least one counting response to the base station in response to the follow-up counting request. The aspects of block 1512 may be performed by MBMS service module 805 and/or counting response generation component 1420 as described with reference to FIG. 14.

FIG. 16 is a conceptual data flow diagram 1600 illustrating the data flow between different modules/means/components in an exemplary apparatus 1602. The apparatus 1602 may be a UE 115. The apparatus 1602 may include a receiving module 1610 that is configured to receive data (e.g., sent to apparatus 1602 by other UEs and/or eNodeBs 105) and a transmission module 1605 that is configured to transmit at least a counting response message (s) to the one or more eNodeBs 105.

The apparatus may include additional modules that perform each of the steps of the algorithm in the aforementioned flow chart of FIG. 15. As such, each step in the aforementioned flow chart of FIG. 15 may be performed by one or more modules of apparatus 1602. The modules may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

In accordance with the present disclosure, the receiving module 1610 may receive system information, counting request message and/or follow-up counting request from a base station 105. The receiving module 1610 may forward the system information to random access parameter component 1405. In some examples, the system information may comprise random access parameters that identify a plurality of random access preambles and/or power control information to support open loop power control. Additionally or alternatively, the receiving module 1610 may further forward counting request messages from the base station 105 to count request receiver component 1410. The counting request may relate to one or more MBMS services provided by the network. In some examples, the counting request may additionally include a response preamble indicator identifying whether the UE 115 should use a base station designated shared preamble or a randomly selected UE preamble.

The counting request may further be forwarded to MBMS service determination component 1415. The MBMS service determination component 1415 may determine whether to respond to the counting request. Based on the determination that a response is to be sent, the MBMS service determination component 1415 may instruct the counting response generation component 1420 to generate a counting response message. The counting response message may be a random access response message that includes a random access preamble based on the response preamble indicator.

In some aspects, the counting response message generated by the counting response generation component 1420 may be forwarded to the transmission module 1605 to be transmitted to the base station 105. In some examples, the counting response message may be transmitted on a shared physical uplink control channel.

FIG. 17 is a diagram 1700 illustrating an example of a hardware implementation for an apparatus employing a processing system 1714. The processing system 1714 may be implemented with bus architecture, represented generally by the bus 1724. The bus 1724 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 1714 and the overall design constraints. The bus 1724 links together various circuits including one or more processors and/or hardware modules, represented by the processor 1704, the

modules

1405, 1410, 1415, 1420 and the computer-readable medium /memory 1706. The bus 1724 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system 1714 may be coupled to a transceiver 1710. The transceiver 1710 is coupled to one or more antennas 1720. The transceiver 1710 provides a means for communicating with various other apparatus over a transmission medium. The transceiver 1710 receives a signal from the one or more antennas 1720, extracts information from the received signal, and provides the extracted information to the processing system 1714, specifically the reception module 1610 described with reference to FIG. 16. In addition, the transceiver 1710 receives information from the processing system 1714, specifically the transmission module 1605 described with reference to FIG. 16, and based on the received information, generates a signal to be applied to the one or more antennas 1720. The processing system 1714 includes a processor 1704 coupled to a computer-readable medium /memory 1706. The processor 1704 is responsible for general processing, including the execution of software stored on the computer-readable medium /memory 1706. The software, when executed by the processor 1704, causes the processing system 1714 to perform the various functions described supra for any particular apparatus. The computer-readable medium /memory 1706 may also be used for storing data that is manipulated by the processor _1404 when executing software. The processing system further includes at least one of the random access parameter component 1405, count request receiver component 1410, MBMS service determination component 1415 and counting response generation component 1420. The components may be software components running in the processor 1704, resident/stored in the computer readable medium /memory 1706, one or more hardware modules coupled to the processor 1704, or some combination thereof. The processing system 1714 may be a component of the UE 650 and may include the memory 660 and/or at least one of the TX processor 668, the RX processor 656, and the controller/processor 659.

In accordance with various aspects of the disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, digital signal processors (DSPs) , field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure.

One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer-readable medium. The computer-readable medium may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip) , an optical disk (e.g., compact disk (CD) , digital versatile disk (DVD) ) , a smart card, a flash memory device (e.g., card, stick, key drive) , random access memory (RAM) , read only memory (ROM) , programmable ROM (PROM) , erasable PROM (EPROM) , electrically erasable PROM (EEPROM) , a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium may be resident in the processing system, external to the processing system, or distributed across multiple entities including the processing system. The computer-readable medium may be embodied in a computer-program product. By way of example, a computer-program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” Unless specifically stated otherwise, the term “some” refers to one or more. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a； b； c； a and b； a and c； b and c； and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for. ”

WHAT IS CLAIMED IS:

Claims

The method for wireless communication, comprising:

transmitting, from a base station, a counting request to one or more user equipments (UEs) , wherein the counting request relates to one or more services of a multimedia broadcast multicast service (MBMS) ；

receiving, in response to the counting request, at least one counting response from the one or more UEs indicating interest in at least one of the one or more services；

determining a measurement of a received power-related characteristic of a channel over which the at least one counting response is received； and

determining an estimation of a number or a range of numbers of UEs interested in the at least one of the one or more services based on the measurement.
The method of claim 1, wherein determining the estimation of the number or the range of numbers of UEs comprises:

determining whether the measurement of the received power-related characteristic satisfies at least one target threshold.
The method of claim 2, further comprising:

transmitting a follow-up counting request to the one or more UEs based on determining that the measurement of the received power-related characteristic is below the at least one target threshold, wherein the follow-up counting request requests the UE to retransmit the at least one counting response；

receiving the at least one counting response from the one or more UEs in response to the follow-up counting request； and

wherein determining the estimation of the number or the range of numbers of UEs interested in the at least one of the one or more services is further based on the at least one counting response.
The method of claim 1, further comprising:

transmitting a response preamble indicator identifying whether the one or more UEs should use a base station designated shared preamble or a randomly selected UE preamble； and

wherein the at least one counting response is a random access response message that includes a random access preamble based on the response preamble indicator.
The method of claim 1, wherein determining the measurement of the received power-related characteristic comprises:

detecting at least one power peak corresponding to a timing advance of at least one of the one or more UEs.
The method of claim 1, wherein transmitting the counting request includes transmitting a UE mode indicator that identifies a UE mode, wherein the UE mode indicator indicates that the response should or should not be transmitted by ones of the one or more UEs in the UE mode, and wherein the UE mode includes a radio resource control (RRC) connected mode or an Idle mode or both.
The method of claim 1, wherein transmitting the counting request comprises transmitting on a broadcast channel, and wherein receiving the at least one counting response comprises receiving on a shared channel.
The method of claim 1, wherein the at least one counting response is a random access response message received on a random access channel, and further comprising:

transmitting a system information message including random access parameters, wherein the random access parameters identify a plurality of random access preambles； and

wherein receiving the random access response message comprises receiving according to a configuration based on the random access parameters.
The method of claim 8, wherein receiving the random access response message according to the configuration based on the random access parameters comprises mapping a plurality of random access preambles with a plurality of group identifiers corresponding to a plurality of services transmitted with the counting request.
The method of claim 9,

wherein transmitting the counting request comprises transmitting a plurality of group identifiers corresponding to a plurality of services；

wherein transmitting the system information message includes transmitting a plurality of random access parameters each corresponding to one of the plurality of group identifiers； and

wherein receiving the random access response message comprises receiving a plurality of random access response messages, wherein at least two of the plurality of random access response messages are received according to at least two respective configurations based on at least two of the plurality of random access parameters.
The method of claim 1, wherein transmitting the counting request comprises transmitting on a broadcast channel, and wherein receiving the at least one counting response comprises receiving on a shared physical uplink control channel.
The method of claim 1, further comprising:

transmitting a system information message comprising power control information.
The method of claim 13, wherein receiving the at least one counting response comprises receiving the at least one counting response following an open loop power control based on the power control information.
The method of claim 1, further comprising:

assigning dedicated resources for receiving at least one counting response, wherein the dedicated resources includes at least one of time or frequency resources； and

wherein receiving the at least one counting response comprises receiving the at least one counting response over the dedicated resources.
The method of claim 1, further comprising:

selecting a bearer for providing the at least one of the one or more services based in part on the estimation.
The method of claim 15, further comprising:

reporting the estimation of the number or the range of numbers of UEs to an MBMS coordination entity (MCE) ； and

wherein selecting the bearer comprises selecting by the MCE based on the estimated number or the range of numbers of UEs in each cell in the multicast-broadcast single-frequency network (MBSFN) area.
An apparatus for wireless communication, comprising:

means for transmitting, from a base station, a counting request to one or more user equipments (UEs) , wherein the counting request relates to one or more services of a multimedia broadcast multicast service (MBMS) ；

means for receiving, in response to the counting request, at least one counting response from the one or more UEs indicating interest in at least one of the one or more services；

means for determining a measurement of a received power-related characteristic of a channel over which the at least one counting response is received； and

means for determining an estimation of a number or a range of numbers of UEs interested in the at least one of the one or more services based on the measurement.
The apparatus of claim 17, wherein means for determining the estimation of the number or the range of numbers of UEs comprises:

means for determining whether the measurement of the received power-related characteristic satisfies at least one target threshold.
The apparatus of claim 18, further comprising:

means for transmitting a follow-up counting request to the one or more UEs based on determining that the measurement of the received power-related characteristic is below the at least one target threshold, wherein the follow-up counting request requests the UE to retransmit the at least one counting response；

means for receiving the at least one counting response from the one or more UEs in response to the follow-up counting request； and

wherein the means for determining the estimation of the number or the range of numbers of UEs interested in the at least one of the one or more services is further based on the at least one counting response .
The apparatus of claim 17, further comprising:

means for transmitting a response preamble indicator identifying whether the one or more UEs should use a base station designated shared preamble or a randomly selected UE preamble； and

wherein the at least one counting response is a random access response message that includes a random access preamble based on the response preamble indicator.
The apparatus of claim 17, wherein the means for determining the measurement of the received power-related characteristic comprises:

means for detecting at least one power peak corresponding to a timing advance of at least one of the one or more UEs.
The apparatus of claim 17, wherein the means for transmitting the counting request includes means for transmitting a UE mode indicator that identifies a UE mode, wherein the UE mode indicator indicates that the response should or should not be transmitted by ones of the one or more UEs in the UE mode, and wherein the UE mode includes a radio resource control (RRC) connected mode or an Idle mode or both.
The apparatus of claim 17, wherein means for transmitting the counting request comprises transmitting on a broadcast channel, and wherein means for receiving the at least one counting response comprises receiving on a shared channel.
The apparatus of claim 17, wherein the at least one counting response is a random access response message received on a random access channel, and further comprising:

means for transmitting a system information message including random access parameters, wherein the random access parameters identify a plurality of random access preambles； and

wherein the means for receiving the random access response message comprises means for receiving according to a configuration based on the random access parameters.
The apparatus of claim 24, wherein the means for receiving the random access response message according to the configuration based on the random access parameters comprises means for mapping a plurality of random access preambles with a plurality of group identifiers corresponding to a plurality of services transmitted with the counting request.
The apparatus of claim 25,

wherein the means for transmitting the counting request comprises means for transmitting a plurality of group identifiers corresponding to a plurality of services；

wherein the means for transmitting the system information message includes means for transmitting a plurality of random access parameters each corresponding to one of the plurality of group identifiers； and

wherein the means for receiving the random access response message comprises means for receiving a plurality of random access response messages, and wherein at least two of the plurality of random access response messages are received according to at least two respective configurations based on at least two of the plurality of random access parameters.
The apparatus of claim 17, wherein the means for transmitting the counting request comprises means for transmitting on a broadcast channel, and wherein the means for receiving the at least one counting response comprises means for receiving on a shared physical uplink control channel.
The apparatus of claim 17, further comprising:

means for transmitting a system information message comprising power control information.
The apparatus of claim 28, wherein the means for receiving the at least one counting response comprises means for receiving the at least one counting response following an open loop power control based on the power control information.
The apparatus of claim 17, further comprising:

means for assigning dedicated resources for receiving at least one counting response, wherein the dedicated resources includes at least one of time or frequency resources； and

wherein the means for receiving the at least one counting response comprises means for receiving the at least one counting response over the dedicated resources.
The apparatus of claim 17, further comprising:

means for selecting a bearer for providing the at least one of the one or more services based in part on the estimation.
The apparatus of claim 31, further comprising:

means for reporting the estimation of the number or the range of numbers of UEs to an MBMS coordination entity (MCE) ； and

wherein the means for selecting the bearer comprises means for selecting by the MCE based on the estimated number or the range of numbers of UEs in each cell in the multicast-broadcast single-frequency network (MBSFN) area.
A computer readable medium storing computer executable code for wireless communication, comprising:

code for transmitting, from a base station, a counting request to one or more user equipments (UEs) , wherein the counting request relates to one or more services of a multimedia broadcast multicast service (MBMS) ；

code for receiving, in response to the counting request, at least one counting response from the one or more UEs indicating interest in at least one of the one or more services；

code for determining a measurement of a received power-related characteristic of a channel over which the at least one counting response is received； and

code for determining an estimation of a number or a range of numbers of UEs interested in the at least one of the one or more services based on the measurement.
The computer readable medium of claim 33, wherein the code for determining the estimation of the number or the range of numbers of UEs comprises:

code for determining whether the measurement of the received power-related characteristic satisfies at least one target threshold.
The computer readable medium of claim 34, further comprising:

code for transmitting a follow-up counting request to the one or more UEs based on determining that the measurement of the received power-related characteristic is below the at least one target threshold, wherein the follow-up counting request requests the UE to retransmit the at least one counting response；

code for receiving the at least one counting response from the one or more UEs in response to the follow-up counting request； and

wherein the code for determining the estimation of the number or the range of numbers of UEs interested in the at least one of the one or more services is further based on the at least one counting response.
The computer readable medium of claim 33, further comprising:

code for transmitting a response preamble indicator identifying whether the one or more UEs should use a base station designated shared preamble or a randomly selected UE preamble； and

wherein the at least one counting response is a random access response message that includes a random access preamble based on the response preamble indicator.
The computer readable medium of claim 33, wherein the code for determining the measurement of the received power-related characteristic comprises:

code for detecting at least one power peak corresponding to a timing advance of at least one of the one or more UEs.
The computer readable medium of claim 33, wherein the code for transmitting the counting request includes code for transmitting a UE mode indicator that identifies a UE mode, wherein the UE mode indicator indicates that the response should or should not be transmitted by ones of the one or more UEs in the UE mode, wherein the UE mode includes a radio resource control (RRC) connected mode or an Idle mode or both.
The computer readable medium of claim 33, wherein the code for transmitting the counting request comprises code for transmitting on a broadcast channel, and wherein the code for receiving the at least one counting response comprises code for receiving on a shared channel.
The computer readable medium of claim 33, wherein the at least one counting response is a random access response message received on a random access channel, and further comprising:

code for transmitting a system information message including random access parameters, wherein the random access parameters identify a plurality of random access preambles； and

wherein the code for receiving the random access response message comprises code for receiving according to a configuration based on the random access parameters.
The computer readable medium of claim 40, wherein the code for receiving the random access response message according to the configuration based on the random access parameters comprises code for mapping a plurality of random access preambles with a plurality of group identifiers corresponding to a plurality of services transmitted with the counting request.
The computer readable medium of claim 41,

wherein the code for transmitting the counting request comprises code for transmitting a plurality of group identifiers corresponding to a plurality of services；

wherein the code for transmitting the system information message includes code for transmitting a plurality of random access parameters each corresponding to one of the plurality of group identifiers； and

wherein the code for receiving the random access response message comprises code for receiving a plurality of random access response messages, wherein at least two of the plurality of random access response messages are received according to at least two respective configurations based on at least two of the plurality of random access parameters.
The computer readable medium of claim 33, wherein the code for transmitting the counting request comprises code for transmitting on a broadcast channel, and wherein the code for receiving the at least one counting response comprises code for receiving on a shared physical uplink control channel.
The computer readable medium of claim 33, further comprising:

code for transmitting a system information message comprising power control information.
The computer readable medium of claim 33, wherein the code for receiving the at least one counting response comprises code for receiving the at least one counting response following an open loop power control based on the power control information.
The computer readable medium of claim 33, further comprising:

code for assigning dedicated resources for receiving at least one counting response, wherein the dedicated resources includes at least one of time or frequency resources； and

wherein the code for receiving the at least one counting response comprises code for receiving the at least one counting response over the dedicated resources.
The computer readable medium of claim 33, further comprising:

code for selecting a bearer for providing the at least one of the one or more services based in part on the estimation.
The computer readable medium of claim 47, further comprising:

code for reporting the estimation of the number or the range of numbers of UEs to an MBMS coordination entity (MCE) ； and

wherein the code for selecting the bearer comprises code for selecting by the MCE based on the estimated number or the range of numbers of UEs in each cell in the multicast-broadcast single-frequency network (MBSFN) area.
An apparatus for wireless communication, comprising:

a processor；

a memory in electronic communication with the processor； and

instructions stored in the memory, the instructions being executable by the processor to cause the apparatus to:

transmit, from a base station, a counting request to one or more user equipments (UEs) , wherein the counting request relates to one or more services of a multimedia broadcast multicast service (MBMS) ；

receive, in response to the counting request, at least one counting response from the one or more UEs indicating interest in at least one of the one or more services；

determine a measurement of a received power-related characteristic of a channel over which the at least one counting response is received； and

determine an estimation of a number or a range of numbers of UEs interested in the at least one of the one or more services based on the measurement.
The apparatus of claim 49, wherein the instructions are further executable by the processor to:

determine whether the measurement of the received power-related characteristic satisfies at least one target threshold.
The apparatus of claim 50, wherein the instructions are further executable by the processor to:

transmit a follow-up counting request to the one or more UEs based on determining that the measurement of the received power-related characteristic is below the at least one target threshold, wherein the follow-up counting request requests the UE to retransmit the at least one counting response；

receive the at least one counting response from the one or more UEs in response to the follow-up counting request； and

wherein determining the estimation of the number or the range of numbers of UEs interested in the at least one of the one or more services is further based on the at least one counting response.
The apparatus of claim 49, wherein the instructions are further executable by the processor to:

transmit a response preamble indicator identifying whether the one or more UEs should use a base station designated shared preamble or a randomly selected UE preamble； and

wherein the at least one counting response is a random access response message that includes a random access preamble based on the response preamble indicator.
The apparatus of claim 49, wherein the instructions are further executable by the processor to:

detect at least one power peak corresponding to a timing advance of at least one of the one or more UEs.
The apparatus of claim 49, wherein transmitting the counting request includes transmitting a UE mode indicator that identifies a UE mode, wherein the UE mode indicator indicates that the response should or should not be transmitted by ones of the one or more UEs in the UE mode, wherein the UE mode includes a radio resource control (RRC) connected mode or an Idle mode or both.
The apparatus of claim 49, wherein transmitting the counting request comprises transmitting on a broadcast channel, and wherein receiving the at least one counting response comprises receiving on a shared channel.
The apparatus of claim 49, wherein the at least one counting response is a random access response message received on a random access channel, and wherein the instructions are further executable by the processor to:

transmit a system information message including random access parameters, wherein the random access parameters identify a plurality of random access preambles； and

wherein receiving the random access response message comprises receiving according to a configuration based on the random access parameters.
The apparatus of claim 56, wherein the instructions are further executable by the processor to:

map a plurality of random access preambles with a plurality of group identifiers corresponding to a plurality of services transmitted with the counting request.
The apparatus of claim 57, wherein the instructions are further executable by the processor to:

transmit a plurality of group identifiers corresponding to a plurality of services；

transmit a plurality of random access parameters each corresponding to one of the plurality of group identifiers； and

receive a plurality of random access response messages, wherein at least two of the plurality of random access response messages are received according to at least two respective configurations based on at least two of the plurality of random access parameters.
The apparatus of 49, further comprising:

select a bearer for providing the at least one of the one or more services based in part on the estimation.
A method for wireless communication, comprising:

receiving, at a user equipment (UE) , a counting request from a base station, wherein the counting request relates to one or more services of a multimedia broadcast multicast service (MBMS) ；

determining whether to respond to the counting request； and

transmitting, in response to the counting request, at least one counting response indicating interest in at least one of the one or more services based on determination that a response is to be sent.
The method of claim 60, further comprising:

receiving a follow-up counting request from the base station, wherein the follow-up counting request requests the UE to retransmit the at least one counting response； and

retransmitting the at least one counting response in response to the follow-up counting request on a shared channel.
The method of claim 60, further comprising:

receiving a response preamble indicator identifying whether the UE should use a base station designated shared preamble or a randomly selected UE preamble； and

wherein the at least one counting response is a random access response message that includes a random access preamble based on the response preamble indicator.
The method of claim 60, wherein receiving the counting request includes receiving a UE mode indicator that identifies a UE mode, wherein the UE mode indicator indicates that the response should or should not be transmitted by the UE in the UE mode, wherein the UE mode includes a radio resource control (RRC) connected mode or an Idle mode or both.
The method of claim 60, wherein receiving the counting request comprises receiving on a broadcast channel, and wherein transmitting the at least one counting response comprises transmitting on a shared channel.
The method of claim 60, wherein the at least one counting response is a random access response message received on a random access channel, and further comprising:

receiving a system information message including random access parameters, wherein the random access parameters identify a plurality of random access preambles； and

wherein transmitting the random access response message comprises transmitting according to a configuration based on the random access parameters.
The method of claim 65, wherein transmitting the random access response message according to the configuration based on the random access parameters comprises mapping a plurality of random access preambles with a plurality of group identifiers corresponding to a plurality of services transmitted with the counting request.
The method of claim 66,

wherein receiving the counting request comprises receiving a plurality of group identifiers corresponding to a plurality of services；

wherein receiving the system information message includes receiving a plurality of random access parameters each corresponding to one of the plurality of group identifiers； and

wherein transmitting the random access response message comprises transmitting a plurality of random access response messages, wherein at least two of the plurality of random access response messages are transmitted according to at least two respective configurations based on at least two of the plurality of random access parameters.
The method of claim 60, wherein receiving the counting request comprises receiving on a broadcast channel, and wherein transmitting the at least one counting response comprises transmitting on a shared physical uplink control channel.
The method of claim 60, further comprising:

receiving a system information message comprising power control information.
The method of claim 69, wherein transmitting the at least one counting response comprises transmitting the at least one counting response following an open loop power control based on the power control information.
An apparatus for wireless communication, comprising:

means for receiving, from a user equipment (UE) , a counting request from a base station, wherein the counting request relates to one or more services of a multimedia broadcast multicast service (MBMS) ；

means for determining whether to respond to the counting request； and

means for transmitting, in response to the counting request, at least one counting response indicating interest in at least one of the one or more services based on determination that a response is to be sent.
The apparatus of claim 71, further comprising:

means for receiving a follow-up counting request from the base station, wherein the follow-up counting request requests the UE to retransmit the at least one counting response； and

means for retransmitting the at least one counting response in response to the follow-up counting request on a shared channel.
The apparatus of claim 71, further comprising:

means for receiving a response preamble indicator identifying whether the UE should use a base station designated shared preamble or a randomly selected UE preamble； and

wherein the at least one counting response is a random access response message that includes a random access preamble based on the response preamble indicator.
The apparatus of claim 71, wherein means for receiving the counting request includes means for receiving a UE mode indicator that identifies a UE mode, wherein the UE mode indicator indicates that the response should or should not be transmitted by the UE in the UE mode, wherein the UE mode includes a radio resource control (RRC) connected mode or an Idle mode or both.
The apparatus of claim 71, wherein means for receiving the counting request comprises means for receiving on a broadcast channel, and wherein transmitting the at least one counting response comprises transmitting on a shared channel.
The apparatus of claim 71, wherein the at least one counting response is a random access response message received on a random access channel, and further comprising:

means for receiving a system information message including random access parameters, wherein the random access parameters identify a plurality of random access preambles； and

wherein means for transmitting the random access response message comprises means for transmitting according to a configuration based on the random access parameters.
The apparatus of claim 76, wherein means for transmitting the random access response message according to the configuration based on the random access parameters comprises means for mapping a plurality of random access preambles with a plurality of group identifiers corresponding to a plurality of services transmitted with the counting request.
The apparatus of claim 77,

wherein means for receiving the counting request comprises means for receiving a plurality of group identifiers corresponding to a plurality of services；

wherein means for receiving the system information message includes means for receiving a plurality of random access parameters each corresponding to one of the plurality of group identifiers； and

wherein means for transmitting the random access response message comprises means for transmitting a plurality of random access response messages, wherein at least two of the plurality of random access response messages are transmitted according to at least two respective configurations based on at least two of the plurality of random access parameters.
The apparatus of claim 71, wherein means for receiving the counting request comprises means for receiving on a broadcast channel, and wherein transmitting the at least one counting response comprises means for transmitting on a shared physical uplink control channel.
The apparatus of claim 71, further comprising:

means for receiving a system information message comprising power control information.
The apparatus of claim 71, wherein means for transmitting the at least one counting response comprises means for transmitting the at least one counting response following an open loop power control based on the power control information.
A computer readable medium storing computer executable code for wireless communication, comprising:

code for receiving, from a user equipment (UE) , a counting request from a base station, wherein the counting request relates to one or more services of a multimedia broadcast multicast service (MBMS) ；

code for determining whether to respond to the counting request； and

code for transmitting, in response to the counting request, at least one counting response indicating interest in at least one of the one or more services based on determination that a response is to be sent.
The computer readable medium of claim 82, further comprising:

code for receiving a follow-up counting request from the base station, wherein the follow-up counting request requests the UE to retransmit the at least one counting response； and

code for retransmitting the at least one counting response in response to the follow-up counting request on a shared channel.
The computer readable medium of claim 82, further comprising:

code for receiving a response preamble indicator identifying whether the UE should use a base station designated shared preamble or a randomly selected UE preamble； and

wherein the at least one counting response is a random access response message that includes a random access preamble based on the response preamble indicator.
The computer readable medium of claim 82, wherein the code for receiving the counting request includes code for receiving a UE mode indicator that identifies a UE mode, wherein the UE mode indicator indicates that the response should or should not be transmitted by the UE in the UE mode, wherein the UE mode includes a radio resource control (RRC) connected mode or an Idle mode or both.
The computer readable medium of claim 82, wherein the code for receiving the counting request comprises code for receiving on a broadcast channel, and wherein transmitting the at least one counting response comprises transmitting on a shared channel.
The computer readable medium of claim 82, wherein the at least one counting response is a random access response message received on a random access channel, and further comprising:

code for receiving a system information message including random access parameters, wherein the random access parameters identify a plurality of random access preambles； and

wherein the code for transmitting the random access response message comprises means for transmitting according to a configuration based on the random access parameters.
The computer readable medium of claim 87, wherein the code for transmitting the random access response message according to the configuration based on the random access parameters comprises code for mapping a plurality of random access preambles with a plurality of group identifiers corresponding to a plurality of services transmitted with the counting request.
The computer readable medium of claim 88,

wherein the code for receiving the counting request comprises code for receiving a plurality of group identifiers corresponding to a plurality of services；

wherein the code for receiving the system information message includes code for receiving a plurality of random access parameters each corresponding to one of the plurality of group identifiers； and

wherein the code for transmitting the random access response message comprises code for transmitting a plurality of random access response messages, wherein at least two of the plurality of random access response messages are transmitted according to at least two respective configurations based on at least two of the plurality of random access parameters.
The computer readable medium of claim 82, wherein the code for receiving the counting request comprises code for receiving on a broadcast channel, and wherein transmitting the at least one counting response comprises code for transmitting on a shared physical uplink control channel.
The computer readable medium of claim 82, further comprising:

code for receiving a system information message comprising power control information.
The computer readable medium of claim 91, wherein the code for transmitting the at least one counting response comprises code for transmitting the at least one counting response following an open loop power control based on the power control information.
An apparatus for wireless communication, comprising:

a processor；

a memory in electronic communication with the processor； and

instructions stored in the memory, the instructions being executable by the processor to cause the apparatus to:

receive, from a user equipment (UE) , a counting request from a base station, wherein the counting request relates to one or more services of a multimedia broadcast multicast service (MBMS) ；

determine whether to respond to the counting request； and

transmit, in response to the counting request, at least one counting response indicating interest in at least one of the one or more services based on determination that a response is to be sent.