Systems, methods, and devices for device-to-device communication mode selection

System, method and device for device-to-device communication mode selection

Systems, methods, and devices for device-to-device communication mode selection

This disclosure relates to device-to-device communication mode selection.

The wireless mobile communication technology uses various standards and protocols to send data between a node (for example, a transmitter or transceiver node) and a wireless device (for example, a mobile communication device). Some wireless devices communicate by using orthogonal frequency division multiple access (OFDMA) in downlink (DL) transmission and single carrier frequency division multiple access (SC-FDMA) in uplink (UL) transmission . Standards and protocols that use Orthogonal Frequency Division Multiplexing (OFDM) for signal transmission include the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) Rel. 8, 9 and 10; Institute of Electrical and Electronic Engineers (IEEE) 802.16 Standards (for example, 802.16e, 802.16m), which are WiMAX (Global Interoperability for Microwave Access) commonly known by industry groups; and IEEE 802.11-2012 standards, which are Wi-Fi commonly known by industry groups.

In the 3GPP Radio Access Network (RAN) LTE system, this node can be an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) node A combination of B (usually referred to as evolved Node B, enhanced Node B, eNodeB, or eNB) and radio network controller (RNC) (which communicates with the wireless device (called user equipment (UE))) . The DL transmission may be a communication from the node (e.g., eNB) to the wireless device (e.g., UE), and the UL transmission may be a communication from the wireless device to the node.

Proximity-based applications and ProSe (ProSe) represent emerging social technology trends. Proximity-based communication (also referred to herein as direct communication, device-to-device (D2D) communication, or peer-to-peer service or communication) is a method by which mobile stations can communicate directly rather than via a network infrastructure A powerful technology for routing data or controlling information to increase network throughput. D2D communication has a wide range of applications. For example, D2D has been proposed for local social networks, content sharing, location-based marketing, service advertising, public safety networks, mobile-to-mobile applications, and other services. D2D communications have attracted attention because of their ability to reduce the load on the core network or RAN, increase the data rate due to direct and short communication paths, provide public safety communication paths, and provide other functions. The introduction of ProSe performance in LTE will allow the 3GPP industry to serve this developing market and serve the urgent needs of several public safety services at the same time. The use of this combination can enable the advantages of economies of scale, because the resulting system can be used for both public safety and non-public safety services, where possible.

<p>102Enhanced Node B</p><p>200Method</p><p>400User Equipment</p><p>402Transmission Mode Components</p><p>404D2D state component</p><p>406Select components</p><p>408Transmission component</p><p>502Performance components</p><p>504SIB components</p><p>506D2D control components</p><p>508RRC components</p><p>600Example method</p><p>700Example method</p><p>800Example method</p>

Figure 1 is a schematic diagram showing an exemplary direct communication state of a wireless communication device.

Figure 2 is a schematic flow chart showing a method for determining the current direct communication status, according to an embodiment.

Figure 3 is a schematic diagram showing an exemplary transition between direct communication states, according to one embodiment.

Figure 4 is a schematic diagram showing the components of a user equipment (UE), according to one embodiment.

Figure 5 is a schematic diagram showing the components of a base station, according to one embodiment.

Figure 6 is a schematic flow chart showing a method for selecting a communication mode, according to one embodiment.

Figure 7 is a schematic flowchart showing another method for selecting a communication mode, according to one embodiment.

Figure 8 is a schematic flow chart showing a method for configuring a communication mode, according to one embodiment.

Figure 9 shows a diagram of a wireless device (e.g., UE) according to an example.

[Content and Implementation of the Invention]

Implementations of the system and method in accordance with the embodiments of the present disclosure are provided below. Although several embodiments have been described, it should be understood that this disclosure is not limited to any one embodiment, but includes many alternatives, modifications, and equivalents. In addition, although many specific details are stated in the following In order to provide a thorough understanding of the embodiments disclosed herein, some embodiments may be implemented without some or all of these details. In addition, for the purpose of clarity, certain technical materials known in the related arts have not been described in detail in order to avoid unnecessarily obscuring the present disclosure.

The wireless mobile communication technology uses various standards and protocols to send data between a node (for example, a transmitter or transceiver node) and a wireless device (for example, a mobile communication device). Some wireless devices communicate by using orthogonal frequency division multiple access (OFDMA) in downlink (DL) transmission and single carrier frequency division multiple access (SC-FDMA) in uplink (UL) transmission . Standards and protocols that use Orthogonal Frequency Division Multiplexing (OFDM) for signal transmission include the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) Rel. 8, 9 and 10; Institute of Electrical and Electronic Engineers (IEEE) 802.16 Standards (for example, 802.16e, 802.16m), which are WiMAX (Global Interoperability for Microwave Access) commonly known by industry groups; and IEEE 802.11-2012 standards, which are Wi-Fi commonly known by industry groups.

In the 3GPP radio access network (RAN) LTE system, the node can be an evolved universal terrestrial radio access network (E-UTRAN) node B (usually also denoted as evolved node B, enhanced node B, eNodeB , Or eNB) and a radio network controller (RNC) that communicates with the wireless device (referred to as user equipment (UE)). The DL transmission may be a communication from the node (e.g., eNB) to the wireless device (e.g., UE), and the UL transmission may be a communication from the wireless device to the node.

Proximity-based applications and ProSe (ProSe) representation Emerging social technology trends. Proximity-based communication (also referred to herein as direct communication, device-to-device (D2D) communication, or peer-to-peer service or communication) is a way of enabling direct communication between mobile stations rather than via a network infrastructure A powerful technology for routing data or controlling information to increase network throughput. D2D communication has a wide range of applications. For example, D2D has been proposed for local social networks, content sharing, location-based marketing, service advertising, public safety networks, mobile-to-mobile applications, and other services. D2D communication has attracted attention because of their ability to reduce the load on the core network or RAN, increase the data rate due to direct and short communication paths, provide public safety communication paths, and provide other functions. The introduction of ProSe performance in LTE will allow the 3GPP industry to serve this developing market and serve the urgent needs of several public safety services at the same time. The use of this combination can enable the advantages of economies of scale, because the resulting system can be used for both public safety and non-public safety services, where possible.

There are various alternatives to achieve direct communication paths between such mobile devices. In one embodiment, the D2D air interface PC5 can use some types of short-range technologies (such as Bluetooth or Wi-Fi), or by reusing the licensed LTE spectrum (such as UL spectrum in FDD LTE system or TDD LTE). UL sub-frame in the system) to be implemented. In addition, D2D communication can generally be divided into two parts. The first part is device discovery, whereby the UE can determine that they are within range and/or can be used for D2D communication. Proximity detection can be assisted by the network infrastructure, can be performed at least in part by the UE, and/or can be performed largely independently of the network infrastructure. The second part is direct communication between UEs, or D2D data communication, which includes building Establish the process of D2D dialogue between UEs and the actual communication of user or application data. D2D communication may or may not be under the continuous control of the mobile network operator (MNO). For example, the UEs may not need to have an active connection with the eNB in order to participate in D2D communication. It should be noted that D2D communication (for example, the second part) can be independently implemented and operated by a D2D capable UE without the support of D2D discovery (for example, the first part).

Currently, D2D direct discovery and communication are being studied and discussed in the Service and System Aspects (SA) and the RAN Working Group (WG) to be designated as part of the LTE-A version 12 specification. During the RAN1 #76 meeting, the following resource allocation for D2D communication (broadcast at the physical layer) was agreed: From the sending UE's point of view, the UE can operate in two modes for resource allocation:

-Mode 1: The eNodeB or rel-10 relay node schedules the exact resources used by the UE to send direct data and direct control information. For future research (FFS): If the data and/or control available resources are restricted, the semi-static resource library Needed

-Mode 2: The UE itself selects resources from the resource library to send direct data and direct control information

FFS: If the data and control resources are the same

FFS: If a semi-static and/or pre-configured resource library for restricted data and/or controlled available resources is required

-UEs with D2D communication capabilities should be targeted for support in the coverage area At least mode 1

-UEs with D2D communication capabilities should support Mode 2 at least at the edge of the coverage area and/or outside the coverage area

-FFS: Definitions outside the coverage, at the edge of the coverage, and in the coverage

For example, the coverage area is defined at least according to the received power of DL

In addition, the following were agreed as working hypotheses by the RAN1 WG during the RAN1 #76 meeting of the scheduled transmission of the D2D broadcast communication:

For mode 2

-The resource library for scheduling assignment is pre-configured and/or semi-statically allocated

Whether the resource library used by FSS for scheduling assignment is the same as the resource library used for D2D data

-The UE itself selects the resource for scheduling assignment from the resource library for scheduling assignment to send its scheduling assignment

For mode 1

-The location of the resource assigned by the broadcast UE to transmit the schedule comes from the eNodeB

-The location of the resource(s) used to transmit the D2D data by the broadcasting UE comes from the eNodeB

So far, the exact standard for determining UE as a UE at the edge of the coverage area and related UE behavior for D2D communication has not been discussed and is still an open issue in 3GPP LTE. In this disclosure, several potential methods are proposed to select one of two communication modes (mode-1 and mode-2) based on eNB configuration or UE autonomous measurement. In this disclosure, several transmission modes A selection mechanism is proposed to solve these open problems, including how a D2D capable UE can select the D2D communication mode between Mode-1 and Mode-2, taking into account such as Radio Resource Control (RRC) or the radio channel assessed by the UE Several factors of the condition.

Figure 1 is a schematic diagram showing possible UE states when D2D communication is triggered. The UE D2D status can provide information about the radio channel environment or conditions that can affect how D2D transmission resources are allocated. Specifically, UE1 has both UL and DL coverage. The D2D state of UE1 may be referred to herein as state-1 or fully in coverage. In this state, the network can configure UE1 to perform D2D communication in mode-1 or mode-2. UE2 has DL coverage but no uplink link because it is within the DL coverage boundary but outside the UL coverage boundary. Therefore, UE2 may only be able to communicate using Mode-2. The D2D state of UE2 may be referred to herein as state-2 or in UL only coverage. UE3 and UE4 are outside the UL and DL coverage of eNB 102 and therefore cannot detect any D2D specific SIB information. Therefore, only Mode-2 communication is possible due to lack of RRC connection with eNB 102. UE3 is displayed outside the UL and DL coverage, but within the physical D2D shared channel signal (PD2DSCH) relay boundary. The D2D state of the UE3 can be referred to as state-3 or within the coverage of part of the network here. UE4 is outside the UL coverage, DL coverage, and the PD2DSCH relay boundary. The D2D state of UE4 may be referred to herein as state-4 or out of network coverage.

In the first optional embodiment, the D2D transmission mode selection is eNB 102 control. With this option, the eNB 102 determines the D2D transmission mode of the D2D capable UE and, in response to obtaining D2D performance information, explicitly configures it for the UE through a dedicated RRC message (for example, RRC connection reconfiguration). In one embodiment, D2D transmission mode-1 can be designated as the default mode for D2D communication when it is detected without a clear eNB configuration. Additionally, the first network connection condition and the second network connection condition discussed below can be used by the UE to autonomously enable the D2D communication mode and thereby slave mode in the case that the UE loses the UL connection with the eNB 102- 1 Move to mode-2. For example, when the UE is within the complete network coverage of the eNB 102, the UE may select mode-1 or mode-2 according to an explicit signal from the eNB 101.

In the second optional embodiment, D2D transmission mode selection is controlled by the UE. For example, the UE may independently decide which transmission mode to use and the transmission mode is not explicitly configured by the eNB 102. Several network connection conditions/standards can be specified for UL connection loss detection in order to give the D2D UE a controlled way to go to mode-2 autonomously in the event of a loss of UL connection with the serving cell eNB 102 and in In the case where the RRC connection can be re-established, return to mode-1.

The metric used by the device to determine whether it loses the UL connection with the serving eNB 102 can be defined by the first network connection condition and the second network condition described below. For example, the UE may assume that it has lost UL coverage/connection when one or more of the first network connection condition and the second network condition are met and then use mode-2 for D2D communication transmission. If the first network connection condition and the second network condition are not met, The UE can independently decide to use mode-1.

The first network connection condition may determine that the attenuation of the signal from the eNB 102 is lower than the threshold signal strength or signal quality. For example, the UE can measure the DL received power level or quality of the shared reference signal (CRS), primary synchronization signal (PSS), and/or secondary synchronization signal (SSS) of a serving cell (such as eNB 102) . For example, reference signal received power (RSRP) or reference signal received quality (RSRQ) based on CRS may be used. If the measured power level or quality is lower than or equal to a predefined threshold, the UE may determine that the first network connection condition is satisfied. In one embodiment, the parameters used to measure the signals can be standardized in the 3GPP standard or configured by the eNB 102, so that consistent measurement can be achieved. Exemplary pre-configured parameters may include filter taps, sampling interval, or the like.

The second network connection condition may determine that the UL connection with the eNB 102 has been lost. For example, the second network condition may be satisfied when the number of consecutive failed random access attempts (ie, no random access response (RAR) is received) is equal to or greater than a predefined threshold. As another example, the second network condition may be satisfied when the number of scheduling requests without UL approval is equal to or greater than a predefined threshold. In one embodiment, when receiving the RAR response after the random access transmission of the D2D resource request, or when receiving the UL approval of the D2D buffer status report (BSR) report, the UE may determine that the second network connection is not (Or no longer be) satisfied. For example, if the second network connection (and/or the first network condition) is not met, the UE may consider that it has a UL connection with the eNB 102 And use mode-1 for D2D transmission.

In one embodiment, the threshold of one or more of the first network connection condition and the second network connection condition may be transmitted via a broadcast system information block message (e.g., eNB 102) from a control node (e.g., eNB 102) For example, SIB) is configured or configured through UE-specific dedicated RRC signaling. Similarly, the threshold values or parameters can be predefined in the 3GPP standard.

In one embodiment, the UE may enter one of the four D2D states discussed above in response to power-on. For example, the UE may make DL measurements to determine the D2D state of the UE and determine the current mode according to the determined D2D state. FIG. 2 is a flowchart showing an embodiment of a method 200 for selecting a D2D state. For example, the UE may execute the method 200 when it is powered on and/or may execute the method 200 repeatedly to determine a new state. The method 200 starts and the UE scans 202 a DL synchronization signal (eg, PSS/SSS) to obtain downlink synchronization with the eNB 102 and then is placed on the cell. The UE decides 204 whether the PSS/SSS is scanned and whether the SIB is successfully decoded. If the UE decides 204 that the PSS/SSS is not successfully scanned or the SIB is not successfully decoded (No at 204), the UE further decides 208 whether it can detect that the D2D resource library configuration from the eNB 102 has been D2D PD2DSCH relayed by a UE (such as UE5 in Figure 1). If so, the UE decides that it is in state-3 (see UE3 in Figure 1). If no at 206, the UE determines that the UE is in state-4 (see UE4 in Figure 1).

If the UE decides 204 that the PSS/SSS is successfully scanned and The SIB is successfully decoded (Yes at 204), and the UE further determines 206 whether the SIB contains the configuration information of the D2D resource base and/or whether the eNB 102 supports the D2D function. If no at 206, the UE returns to scanning 202 PSS/SSS signals and decoding SIB. If yes in 206, the UE tries to perform the RRC connection setup procedure to establish and detect the eNB 102 RRC connection. If the RRC connection setup procedure is unsuccessful (No at 214), the UE determines that the UE is in state-2. If the RRC connection setup procedure is successful (Yes at 214), the UE determines 218 whether the D2D communication is triggered by the upper layer of the UE. For example, the UE may decide whether the application layer, RRC layer, or other layer indicates that D2D transmission should be performed. If no at 218, the UE can continue to wait until the D2D communication is triggered by the upper layers. If/when the D2D communication is triggered by the upper layer (Yes at 218), the UE makes one or more of the following at 220: implement a random access channel (RACH), send a scheduling request to request D2D communication resource allocation (SR), and/or measure the received power/quality of the DL (for example, measure RSRP or RSRQ). The UE determines 222 whether the first network connection and/or the second network conditions are met. In one embodiment, if the first and second network conditions are met (Yes at 222), the UE determines that the UE is in state-2 (see UE2 in Figure 1). If the first or second network condition is not met (No at 222), the UE determines that the UE is in state-1 (see UE1 in Figure 1).

Table 1 below shows the UE actions and D2D communication mode selection in each D2D state.

<tables><img he="2988" wi="2121" file="tw201737745a_d0001.tif" img-content="drawing" img-format="tif" orientation="portrait" inline="no" /></tables>

In one embodiment, different actions/behavior are performed in each state in order to achieve the D2D communication design goal and enable autonomous D2D state transition. Figure 3 shows an example transition between communication states. Table 2 below provides example measurements and procedures performed by the UE in each state to determine whether to transition to a new state.

<tables><img he="2345" wi="2157" file="tw201737745a_d0002.tif" img-content="drawing" img-format="tif" orientation="portrait" inline="no" /></tables><tables><img he="1394" wi="2212" file="tw201737745a_d0003.tif" img-content="drawing" img-format="tif" orientation="portrait" inline="no" /></tables>

In the third optional embodiment, the D2D transition mode selection is controlled by the UE according to the RRC state. For example, when the D2D communication is started, the UE can autonomously select the transmission mode of the D2D communication according to the RRC status, and the RRC status can be RRC_Idle or RRC_Connected. In particular, a UE in RRC_Connected can use transmission mode-1 to perform D2D communication, and a UE in RRC_Idle can use transmission mode-2.

The first optional embodiment, the second optional embodiment, and the third optional embodiment are presented for illustrative purposes only. Although the first optional embodiment, the second optional embodiment, and the third optional embodiment are individually discussed above, some embodiments include a combination of one or more aspects of each of the optional embodiments . For example, the UE may operate according to the second optional embodiment when no eNB 102 is detected, but when the UE has a connection with the eNB 102 Then operate according to the first optional embodiment or the second optional embodiment.

FIG. 4 is a schematic block diagram of the UE 400 showing some components used to select the D2D communication mode. Some components of UE 400 are not shown to avoid obscuring the present disclosure. The UE 400 includes a transmission mode component 402, a D2D state component 404, a selection component 406, and a transmission component 408. The components 402-408 are presented by way of example only and may not be included in all embodiments.

The transmission mode component 402 selectively allocates D2D communication resources according to a plurality of transmission modes. The plurality of transmission modes include a first transmission mode in which the resources used by the UE 400 are specifically allocated by one of the Node B and the eNB 102, and a second transmission mode in which the UE 400 selects the resources from the available resource library . In one embodiment, the first transmission mode may include the mode-1 discussed herein and the second transmission mode may include the mode-2 discussed herein.

The D2D status component 404 determines the direct communication status of the UE 400 with respect to the eNB 102 (for example, the D2D status). In one embodiment, the D2D status component 404 determines whether the UE 400 is outside the network coverage. For example, the D2D status component 404 can determine whether one or more of the first and second network connection conditions are satisfied. In one embodiment, the D2D status component 404 determines that the UE 400 is outside the network coverage area based on one or more of the following: the measured power level or signal quality of the reference signal from the Node B or eNB 102 is less than Or equal to the predefined cell threshold; and the number of random access attempts for failures not receiving UL approval is greater than or equal to the predefined attempt threshold.

In one embodiment, the D2D state component 404 determines whether the UE 400 is in the connected RRC state or not in the connected RRC state. For example, the D2D state component 404 may determine whether the UE 400 is in the RRC_Connected state or the RRC_Idle state.

In one embodiment, the D2D state component 404 determines whether the UE 400 is in one or more of the four D2D states discussed in relation to Figures 1 and 2. In one embodiment, the D2D state component 404 is configured to determine whether the UE 400 is in a first D2D state (such as state-1), a second D2D state (such as state-2), and a third D2D state (such as state-3). , Or the fourth D2D state (such as state-4). In one embodiment, the UE 400 is in the first D2D state when the UE 400 is within the UL coverage of the eNB and within the DL coverage. In one embodiment, the UE 400 is in the second D2D state when the UE 400 is outside the UL coverage of the eNB and within the DL coverage. In one embodiment, the UE 400 is in the third D2D state when the UE 400 is within a part of the network coverage. For example, the UE 400 may be in a partial network coverage area when the UE 400 is outside the UL coverage area and outside the DL coverage area but is within the D2D range of another UE in the first D2D state (for example, see section 1 In the figure, UE3 is part of the network coverage because it can receive PD2DSCH from UE5). For example, the D2D status component 404 can determine the current D2D status according to whether the PD2DSCH is detected. In one embodiment, the UE 400 is in the UE 400 is in the fourth D2D state when it is outside the network coverage area and part of the network coverage area.

In one embodiment, the D2D state component 404 is configured To determine/detect the transitions between the D2D states according to one or more transition rules, such as the transition rules shown in Table 2 and shown in Figure 3. In one embodiment, the D2D state component 404 is configured to determine the initial D2D state and then determine one or more subsequent D2D states.

The selection component 406 is configured to select the transmission mode of the UE 400 for use during D2D communication, such as one of the communication mode-1 or the mode-2 discussed herein. In one embodiment, the selection component 406 selects based on a signal from the eNB 102 that specifically indicates the selected transmission mode. For example, the eNB 102 can send and the selection component 406 can receive an RRC message that includes information indicating the selected transmission mode. In one embodiment, the selection component 406 can receive the RRC message in response to the UE 400 sending performance information indicating the D2D performance of the UE 400. In one embodiment, when the signal from the eNB 102 that does not specify the selected transmission mode can be detected, the selection component 406 may select to include a plurality of available transmission modes when the signal does not specify the selected transmission mode. The default mode of one of them. For example, the selection module 406 may be preset to use the mode-1 or the mode-2 when the selection component 406 does not receive a signal that explicitly configures the communication mode.

In one embodiment, the selection component 406 is configured to select the transmission mode according to the RRC connection status of the UE 400 and the eNB 102 or other nodes. For example, the selection component 406 can select the transmission mode according to the D2D state determined by the D2D state component 404. For example, the selection component 406 may select the first transmission mode (e.g., mode-1) when the UE 400 is in the RRC_Connected state and select the first transmission mode (e.g., mode-2) when the UE 400 is in the RRC_Idle state.

In one embodiment, the selection component 406 is configured to respond to the current D2D state (such as the state-1, state-2, state-3, and state-4 discussed herein) to autonomously select one of the plurality of transmission modes By. In one embodiment, the selection component 406 selects the mode based on the state determined by the D2D state component 404. For example, the selection component 406 can select the current mode according to Table 1 and/or Figure 2. In one embodiment, the selection component 406 is configured to select the first transmission mode for the first D2D state and select the second transmission mode for the second D2D state, the third D2D state, and the fourth D2D state . The selection component 406 can also monitor the current situation to determine the transition between the D2D states according to one or more transition rules. For example, the selection component 406 can determine when it needs to transition to a new state according to Figure 3 and/or Table 2.

The transmission component 408 is configured to transmit a signal in the frequency resource selected according to the selected transmission mode. For example, the transmission component 408 may transmit a signal within a resource specifically allocated by the eNB 102 or may transmit a signal within a resource selected by the UE 400 from a resource library. The resource library may be pre-configured or defined by the eNB 102 or the network infrastructure.

Figure 5 is a schematic block diagram of the eNB 102 showing some components used to specify the D2D transmission mode. Some components of the eNB 102 are not shown to avoid obscuring the disclosure. The eNB 102 includes a performance component 502, a SIB component 504, a D2D control component 506, and an RRC component 508. The components 502-508 are only proposed by examples and may not all be included in all embodiments.

The performance component 502 is configured to receive instructions from the UE 400 The UE 400 is able to perform D2D communication performance information by using the 3GPP communication standard. In one embodiment, the performance component 502 may receive the performance information after a communication session (such as an RRC session) with the UE 400 has been established.

The SIB component 504 is configured to broadcast an SIB indicating a D2D resource library of resources that can be used for D2D communication or discovery. For example, the resource library may include one or more D2D discovery areas, D2D communication areas, or the like that the UE 400 can use to send D2D control or information signals. In one embodiment, the SIB information can be received by all UEs in the DL coverage area (such as UE1 and UE2 in Figure 1). In one embodiment, even the UE 400 outside the DL coverage area but within the PD2DSCH relay boundary can receive the SIB information, because the UE in the coverage area can forward the resource library configuration (for example, UE3 in Figure 1 includes resource PD2DSCH of library configuration).

The D2D control component 506 is configured to determine the transmission mode of the UE 400, such as communication mode-1 or mode-2 discussed herein. The D2D control component 506 can select the mode of the UE 400 according to the current network load, the signal strength from the UE 400, or other performance parameters of the eNB 102 or the network. In one embodiment, the D2D control component 506 may decide that the UE 400 connected to the eNB 102 should use Mode-2 to reduce the signaling requirements of the eNB 102.

The RRC component 508 is configured to indicate the transmission mode to the UE 400 by using RRC signaling. For example, the RRC component 508 can provide the UE 400 with a message indicating the specific selected by the D2D control component 506 The transmission mode (for example, mode-1 or mode-2 discussed herein) is used by a specific UE 400. In one embodiment, the RRC component 508 is configured to indicate the transmission mode in response to the performance component 502 receiving performance information from the UE 400. In one embodiment, the RRC component 508 may further send an RRC message that permits the UE 400 to access the UL channel for D2D communication or discovery. For example, the RRC component 508 may grant access in response to the UE 400 requesting access to the channel to send D2D discovery, data, or control signals.

FIG. 6 is a schematic flowchart showing an exemplary method 600 for selecting a communication mode of D2D communication. The method 600 may be implemented by a wireless communication device, such as the UE 400 in FIG. 4.

The method 600 starts and the transmission mode component 402 selectively allocates 602 resources for D2D communication according to a plurality of transmission modes. For example, the transmission mode component 402 can select a first transmission mode (such as mode-1) in which the resources used by the UE 400 are specifically allocated by one of the Node B and the eNB 102, or in which the UE 400 selects the resource from a library of available resources. The second transmission mode of equal resources (such as mode-2).

The selection component 406 is configured to select 604 the transmission mode based on a signal that specifically indicates the selected transmission mode. For example, the selection component 406 may select 604 the transmission mode based on the RRC message received from the eNB 102. The transmission component 408 transmits 606 the signal using the frequency resource selected according to the selected transmission mode. For example, if the selection component 406 selects mode-1, the transmission component 408 may use the exact resources allocated by the eNB 102 to send D2D data or control information.

FIG. 7 is a schematic flowchart showing an exemplary method 700 for selecting a communication mode of D2D communication. The method 700 may be implemented by a wireless communication device, such as the UE 400 in FIG. 4.

The method 700 starts and the D2D status component 404 determines 702 the direct communication status. For example, the D2D status component 404 can identify the radio environment with respect to the eNB 102. In one embodiment, the D2D state may include the RRC connection state, regardless of the DL or UL signal from the base station, or other information about the radio environment of the UE 102 location. In one embodiment, the D2D communication status can indicate whether the UE 400 can communicate with a communication network or similar nodes. For example, the D2D state component 404 can determine 702 whether the UE 400 is in an RRC connected or not in an RRC connected state. As another example, the D2D state component 404 may determine 702 whether the UE 400 is in any of state-1, state-2, state-3, or state-4, as discussed herein. For example, the D2D status component 404 can determine 702 the current status according to the method in FIG. 2.

The selection component 406 selects 704 the current transmission mode according to the direct communication status, for example, the direct communication status 702 determined by the D2D status component 404. In one embodiment, the current transmission mode may include a first transmission mode in which the resources used by the wireless communication device are specifically allocated by the base station or in which the wireless communication device selects one of the resources from a library of available resources. The second transmission mode. For example, the current transmission mode may include any of the modes discussed herein.

The transmission component 408 sends 706 the direct communication according to the current transmission mode. For example, the transmission component 408 can be selected based on the selection component 406 Select 704 mode to send 706 D2D data or control signals.

FIG. 8 is a schematic flowchart illustrating an exemplary method 800 for configuring the communication mode of D2D communication. The method 800 may be performed by a base station, such as the eNB 102 in FIG. 5.

The method 800 starts and the SIB component 504 broadcasts 802 the SIBs of the D2D resource library indicating the resources available for D2D communication or discovery. For example, the SIB component 504 may send one or more SIBs for reception by any UE 400 within range of the eNB 102. Therefore, all UEs 400 within the range of the eNB 102 can receive the D2D resource library configuration and know which resource can be used for D2D data or control communication.

The D2D control component 506 decides 804 the transmission mode of the UE 400. For example, the D2D control component 506 may decide 804 a specific transmission mode for a specific UE 400. In one embodiment, the D2D control component 506 can determine 804 the transmission mode according to the load on the eNB 102, the D2D status of the UE 400, or any other information. The RRC component 508 indicates 806 the transmission mode to the UE 400 by using RRC signaling. For example, the RRC component 508 indicates 806 that the transmission mode of 804 is determined by the D2D control component 506.

Figure 9 provides an example diagram of a mobile device, such as a UE, a mobile station (MS), a mobile wireless device, a mobile communication device, a tablet, a mobile phone, or another type of mobile wireless device. The mobile device may include one or more antennas, configured to communicate with a node, a macro node, a low power node (LPN), or a transmitting station (such as a base station (BS), eNB, baseband unit (BBU), remote Radio front end (RRH), remote radio equipment (RRE), relay station (RS), radio equipment (RE), or another type of wireless wide area network (WWAN) AP) communication. The mobile device can be configured to communicate by using at least one wireless communication standard, including 3GPP LTE, WiMAX, High Speed Packet Access (HSPA), Bluetooth, and Wi-Fi. The mobile device can communicate by using individual antennas for each wireless communication standard or by using a shared antenna for multiple wireless communication standards. The mobile device can communicate in WLAN, wireless personal area network (WPAN), and/or WWAN.

Figure 9 also provides an illustration of a microphone and one or more speakers that can be used for audio input and output from the mobile device. The display screen may be a liquid crystal display (LCD) screen or other types of display screens, such as an organic light emitting diode (OLED) display. The display screen can be configured as a touch screen. The touch screen can use capacitive, resistive, or another type of touch screen technology. Application processors and graphics processors can be coupled to internal memory to provide processing and display performance. The non-volatile memory port can also be used to provide data input/output options to the user. The non-volatile memory port can also be used to expand the memory performance of the mobile device. The keyboard can be integrated in the mobile device or wirelessly connected to the mobile device to provide additional user input. The virtual keyboard can also be provided by using the touch screen.

Instance

The following examples refer to additional embodiments.

Example 1 is a UE, which includes a transmission mode component, selection Select components, and transmission components. The transmission mode component is configured to selectively allocate resources for device-to-device communication according to a plurality of transmission modes. The plurality of transmission modes include a first transmission mode in which the resources used by the UE are specifically allocated by one of a Node B and an eNB, and a second transmission mode in which the UE selects the resources from an available resource library. The selection component is configured to select one of the plurality of transmission modes as the selected transmission mode according to a signal from the base station that specifically indicates the selected transmission mode. The transmission component is configured to transmit a signal in a frequency resource selected according to the selected transmission mode.

In example 2, the selection component of example 1 selects the selected transmission mode based on the RRC message containing information indicating the selected transmission mode.

In Example 3, the UE of any of Examples 1-2 receives the RRC message in response to sending performance information indicating the device-to-device performance of the UE.

In Example 4, the selection component of any one of Examples 1-3 is further configured to select a default mode including one of the plurality of transmission modes when there is no signal specifically indicating the selected transmission mode.

In Example 5, the UE of any of Examples 1-4 further includes a device-to-device status component configured to determine when the UE is outside the network coverage.

In Example 6, the device-to-device status component of any one of Examples 1-5 determines that the UE is outside the network coverage area according to one or more of the following: one of the reference signals from the Node B or the eNB already The measured power level or signal quality is less than or equal to the predefined cell threshold; and the number of random access attempts for failures not receiving UL approval is greater than or equal to the predefined attempt threshold.

In Example 7, the UE of any of Examples 1-6 further includes a device-to-device status component configured to determine the current device-to-device status of the UE. The selection component is further configured to autonomously select one of the plurality of transmission modes in response to the current device-to-device state. The current device-to-device status includes one or more of the following: a first device-to-device status, where the UE is within the UL coverage of the Node B or the eNB and within the DL coverage; the second device-to-device status , Where the UE is outside the UL coverage of the Node B or the eNB and is within the DL coverage; the third device-to-device state, where the UE is in a part of the network coverage, which is part of the network coverage Includes the UE outside the UL coverage area and outside the DL coverage area but within the device-to-device range of another UE in the first device-to-device state; and the fourth device-to-device state, where the UE is in the network Outside the coverage area and outside part of the network coverage area.

In Example 8, the selection component of any one of Examples 1-7 is configured to select the first transmission mode for the first device-to-device state and select the second transmission mode for the second device-to-device state State, the third device-to-device state, and the fourth device-to-device state. The device-to-device state component is further configured to determine the device-to-device state transitions according to one or more transition rules.

Example 9 is a wireless communication device configured to determine the The direct communication status of the wireless communication device with respect to the base station. The wireless communication device is configured to select the current transmission mode according to the direct communication state. The current transmission mode includes one of the following: a first transmission mode in which the resources used by the wireless communication device are specifically allocated by the base station; and a first transmission mode in which the wireless communication device selects the resources from the available resource library Two transmission mode. The wireless communication device is configured to send direct communication according to the current transmission mode.

In Example 10, the wireless communication device in Example 9 includes a UE and the base station includes an eNB. Determining the direct communication state includes determining whether the UE is in the connected RRC state or not in the connected RRC state.

In Example 11, selecting the current transmission mode in any of Examples 9-10 includes selecting the first transmission mode when the UE is in the RRC connected state and selecting when the UE is not in the RRC connected state The second transmission mode.

In Example 12, determining the direct communication state in any of Examples 9-11 includes determining the current device-to-device (D2D) state, which includes one of the following: the first D2D state, where the wireless communication device is in the The UL coverage of the base station and the DL coverage; the second D2D state, where the wireless communication device is outside the UL coverage of the base station and within the DL coverage; the third D2D state, where the wireless communication device In part of the network coverage area, which includes the wireless communication device outside the UL coverage area and outside the DL coverage area but in another UE in the first D2D state. Within the D2D range; and the fourth D2D state, in which the wireless communication device is outside the network coverage area and part of the network coverage area.

In Example 13, selecting the current transmission mode in any of Examples 9-12 includes selecting the first transmission mode for the first D2D state and selecting the second transmission mode for the second D2D state, Three D2D states, and a fourth D2D state.

In Example 14, the determination of the direct communication state in any of Examples 9-13 includes determining the initial D2D state and further includes determining one or more subsequent D2D states, wherein the subsequent D2D states are based on one or more transition rules To choose.

In Example 15A, the transition rules of Example 14 include one or more of the following: when RRC connection establishment or re-establishment is successfully completed, transition from the second D2D state to the first state; in PPS or SSS The detected SIB message containing the D2D resource library configuration is successfully decoded, the RRC connection establishment or re-establishment is successfully completed, and the signal strength of the detected PSS or SSS exceeds the pre-configured signal strength or continuous failure without UL approval When the number of random access attempts or SRs is less than the predefined threshold, transition from the third D2D state or the fourth D2D state to the first D2D state; the signal strength of the detected PSS or SSS exceeds the pre-configured signal When the intensity or the number of random access attempts with continuous failures without UL approval or the number of SRs is less than the predefined threshold, transition from the first D2D state to the second D2D state; when the PSS/SSS is detected, the D2D resource library is included The configured SIB message is successfully decoded, the RRC connection establishment or re-establishment failure, and the message of the detected PSS or SSS When the signal strength is lower than or equal to the pre-configured signal strength, or the number of random access attempts with consecutive failures without UL approval, or the number of SRs is not less than the pre-defined threshold, the third D2D state or the fourth D2D state is transitioned to the The second D2D state; when the RLM indicates that the lower layer is out of synchronization, when the UE cannot recover the radio link synchronization with the eNB within a predefined time period, and the D2D resources that are detected on the PD2DSS channel and sent on the PD2DSCH When the library configuration is successfully decoded, transition from the first D2D state or the second D2D state to the third D2D state; when the PD2DSS channel is detected and the D2D resource library configuration sent on the PD2DSCH is successfully decoded, from The fourth D2D state transitions to the third D2D state; when the RLM indicates that the lower layer is out of synchronization, when the UE cannot recover synchronization with the eNB's radio link within a predefined time period, and when no PD2DSS channel is detected When there is no PD2DSS channel and no PSS/SSS is detected, transition from the third D2D state to the fourth D2D state .

In Example 15B, the determination of the current D2D state in any of Examples 9-14 includes determining that the wireless communication device is not in the first D2D in response to one or more of the following: reference signal from the base station The measured power level or signal quality is less than or equal to the pre-defined cell threshold; and the number of random access attempts for failures not receiving UL approval is greater than or equal to the pre-defined trial threshold.

In Example 16, the wireless communication device of any one of Examples 9-15 is further configured to scan the entity PD2DSCH, where it is determined The current D2D state includes a decision based on whether the PD2DSCH is detected.

Example 17 is an eNB, which includes a SIB component, a D2D control component, and an RRC component. The SIB component is configured to broadcast the SIB indicating the D2D resource library of resources that can be used for D2D communication or discovery. The D2D control component is configured to determine the transmission mode of the UE. The transmission mode includes one of the following: a first transmission mode in which the resources used by the UE are specifically allocated by the eNB, and a second transmission mode in which the UE selects the resources from a library of available resources. The RRC component is configured to indicate the transmission mode to the UE by using RRC signaling.

In Example 18, the RRC component of Example 17 is further configured to permit the UE to access the UL channel for D2D communication or discovery.

In Example 19, the eNB of any of Examples 16-17 further includes a performance component configured to receive performance information from the UE indicating that the UE can perform D2D communication by using the 3GPP communication standard.

In Example 20, the RRC component in any of Examples 16-18 is configured to indicate the transmission mode in response to receiving the performance information.

Example 21 is a method that includes selectively allocating resources to device-to-device communication based on a plurality of transmission modes. The plurality of transmission modes include a first transmission mode in which resources used by the UE are specifically allocated by one of a Node B and an eNB, and a first transmission mode in which the UE obtains resources from available resources. The source library selects the second transmission mode of the resources. The method includes selecting one of the plurality of transmission modes as the selected transmission mode at the UE according to a signal from the base station that specifically indicates the selected transmission mode. The method includes transmitting a signal with a frequency resource selected according to the selected transmission mode.

In Example 22, the selection of the selected transmission mode in Example 21 includes selection based on the RRC message indicating the information of the selected transmission mode.

In Example 23, the method of any of Examples 21-22 includes receiving the RRC message in response to sending performance information indicating the device-to-device performance of the UE.

In Example 24, the selection in any of Examples 21-23 includes selecting a default mode that includes one of the plurality of transmission modes when the signal does not specify the selected transmission mode.

In Example 25, the method of any of Examples 21-24 further includes deciding when the UE is outside of network coverage.

In Example 26, the method of any one of Examples 21-25 further includes determining that the UE is outside the network coverage area according to one or more of the following: the amount of reference signal from the Node B or the eNB The measured power level or signal quality is less than or equal to the predefined cell threshold; and the number of random access attempts for failures not receiving UL approval is greater than or equal to the predefined try threshold.

In Example 27, the method of any one of Examples 21-26 further includes determining the current device-to-device state of the UE, and selecting includes autonomously selecting the plurality of transmissions in response to the current device-to-device state Mode one, wherein the current device-to-device state includes one or more of the following: a first device-to-device state, in which the UE is within the UL coverage of the Node B or the eNB and within the DL coverage; The second device-to-device state, where the UE is outside the UL coverage of the Node B or the eNB, and within the DL coverage; the third device-to-device state, where the UE is in the partial network coverage, where Part of the network coverage includes the UE outside the UL coverage area and outside the DL coverage area but within the device-to-device range of another UE in the first device-to-device state; and the fourth device-to-device state, The UE is outside the network coverage area and part of the network coverage area.

In Example 28, the autonomous selection in Example 27 includes selecting the first transmission mode for the first device-to-device state and selecting the second transmission mode for the second device-to-device state, and the third device-to-device state. The state and the fourth device-to-device state, and the method further includes determining the transition between the device-to-device states according to one or more transition rules.

Example 29 is a method, which includes determining the direct communication status of the wireless communication device with respect to the base station. The method further includes selecting a current transmission mode according to the direct communication state, wherein the current transmission mode includes one or more of the following: the first transmission in which the resource used by the wireless communication device is specifically allocated by the base station Mode; and the second transmission mode in which the wireless communication device selects the resources from the available resource library. The method further includes sending a direct communication according to the current transmission mode.

In Example 30, the wireless communication device of Example 29 includes a UE and the base station includes an eNB. Determining the direct communication state includes determining whether the UE is in the connected RRC state or not in the connected RRC state.

In Example 31, the selection of the current transmission mode in any of Examples 29-30 includes selecting the first transmission mode when the UE is in the RRC connected state and selecting when the UE is not in the RRC connected state The second transmission mode.

In Example 32, the determination of the direct communication state in any one of Examples 29-31 includes determining the current D2D state, which includes one of the following: the first D2D state, where the wireless communication device is covered by the UL of the base station Within the range and within the DL coverage; the second D2D state, in which the wireless communication device is outside the UL coverage of the base station and within the DL coverage; the third D2D state, in which the wireless communication device is part of the network Coverage, including part of the network coverage area including the wireless communication device outside the UL coverage area and outside the DL coverage area but within the D2D range of another UE in the first D2D state; and the fourth D2D Status, where the wireless communication device is outside the network coverage area and part of the network coverage area.

In Example 33, the selection of the current transmission mode in Example 32 includes selecting the first transmission mode for the first D2D state and selecting the second transmission mode for the second D2D state, the third D2D state, and the first D2D state. Four D2D states.

In Example 34, the decision in any of Examples 32-33 The direct communication state includes determining the initial D2D state and further includes determining one or more subsequent D2D states, wherein the subsequent D2D states are selected according to one or more transition rules.

In Example 35, the determination of the current D2D state in any one of Examples 32-34 includes determining that the wireless communication device is not in the first D2D in response to one or more of the following: reference signal from the base station The measured power level or signal quality is less than or equal to the predefined cell threshold; and the number of random access attempts for failures not receiving UL approval is greater than or equal to the predefined try threshold.

In Example 36, the method of any one of Examples 29-35 further includes scanning the PD2DSCH, wherein determining the current D2D state includes determining based on whether the PD2DSCH is detected.

Example 37 is a method that includes broadcasting an SIB indicating a D2D resource library of resources that can be used for D2D communication or discovery. The method includes deciding the transmission mode of the UE. The transmission mode includes one of the following: a first transmission mode in which the resources used by the UE are specifically allocated by the eNB, and a second transmission mode in which the UE selects the resources from a library of available resources. The method includes indicating the transmission mode to the UE by using RRC signaling.

In Example 38, the method of Example 37 further includes permitting the UE to access the UL channel for D2D communication or discovery.

In Example 39, the method of any of Examples 37-38 further includes receiving performance information from the UE indicating that the UE can perform D2D communication by using the 3GPP communication standard.

In Example 40, the indication in Example 39 includes indicating the transmission mode in response to receiving the performance information.

Example 41 is a device that includes means to perform the methods of any of Examples 21-40.

Example 42 is a machine-readable storage that includes machine-readable instructions that, when executed, implement the method of any one of Examples 21-40 or a device that implements any one of Examples 21-40.

Various technologies, or some aspects or parts thereof, can take the form of program codes (ie instructions) embodied in tangible media, such as floppy disks, CD-ROMs, hard drives, non-transitory computer readable storage A medium, or any other machine-readable storage medium (wherein when the code is loaded into a machine such as a computer and executed by the machine, the machine becomes a device for implementing the various technologies). In the case of a program code executed on a programmable computer, the computing device may include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one Input device, and at least one output device. The volatile and non-volatile memory and/or storage element can be RAM, EPROM, flash drive, optical drive, magnetic hard drive, or another medium for storing electronic data. The eNB (or other base station) and UE (or other mobile station) may also include a transceiver component, a counter component, a processing component, and/or a clock component or a timer component. One or more programs that can implement or utilize the various technologies described herein can use application programming interfaces (APIs), reusable controls, and the like. Such programs may be implemented in high-level procedures or object-oriented programming languages and communicate with computer systems. News. However, the program(s) may be implemented in combination or machine language as needed. In any case, the language can be a compiled or literal language, and combined with hardware implementations.

It should be understood that many functional units described in this specification can be implemented as one or more components, which is a term used to more specifically emphasize their implementation independence. For example, the component can be implemented as a hardware circuit including a traditional very large integrated (VLSI) circuit or a gate array, an off-the-shelf semiconductor (such as a logic chip, a transistor), or other discrete components. Components can also be implemented in programmable hardware devices, such as field-effect programmable gate arrays, programmable array logic, programmable logic devices, or the like.

The components can also be implemented in software executed by various types of processors. The identified components of the executable code may, for example, include one or more physical or logical blocks of computer instructions, which may be composed of, for example, objects, programs, or functions. However, the executable files of the identified components do not need to be physically located together, but can contain different instructions stored in different locations, which when logically combined together contain the component and achieve the stated purpose of the component .

Indeed, the components of the executable code can be a single instruction or many instructions, and can even be distributed across several different code segments, in different programs, and across several memory devices. Similarly, the operating data can be identified and shown in the component here, and may be embodied in any suitable form and composed in any suitable type of data structure. The operating data can be collected as a single data set, or can be distributed across different storage devices Different locations, and at least part of them can exist as electronic signals on the system or on the Internet. These components can be passive or active and include agents that are operable to perform the required functions.

References to "examples" throughout this specification mean that the specific features, structures, or characteristics described for the example are included in at least one embodiment of the present disclosure. Therefore, the appearances of the word "in an example" in various places in this specification do not necessarily all refer to the same embodiment.

As used herein, a plurality of items, structural elements, constituent elements, and/or materials may be presented in a common list for convenience. However, these lists should be interpreted as if the components of the list are individually identified as separate and unique components. Therefore, individual components of such a list should not be interpreted as de facto equivalents of any other components of the same list based on their presentation in a common group without indication to the contrary. In addition, various embodiments and examples of the present disclosure may be mentioned here along with alternatives to various components thereof. It is understood that such embodiments, examples, and substitutes are not interpreted as de facto equivalents to each other, but are interpreted as individual and autonomous expressions of this disclosure.

Although the foregoing has been described in some details for clarity, it will be obvious that certain changes and modifications can be made without departing from the principle. It should be noted that there are many alternative ways to implement both the programs and equipment described here. Therefore, the present embodiment is regarded as illustrative and non-limiting.

Those familiar with the art will understand that many changes can be made to the details of the above embodiments without departing from the implicit principles of the present disclosure. This disclosure Therefore, the scope should only be determined by the scope of the following patent applications.

Various technologies, or some aspects or parts thereof, can take the form of program codes (ie instructions) embodied in tangible media, such as floppy disks, CD-ROMs, hard drives, non-transitory computer readable storage A medium, or any other machine-readable storage medium (where the code is loaded into a machine such as a computer and executed by the machine, the machine becomes a device for implementing these various technologies). In the case of a program code executed on a programmable computer, the computing device may include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one Input device, and at least one output device. The volatile and non-volatile memory and/or storage element can be RAM, EPROM, flash drive, optical drive, magnetic hard drive, or another medium for storing electronic data. The eNB (or other base station) and UE (or other mobile station) may also include a transceiver component, a counter component, a processing component, and/or a clock component or a timer component. One or more programs that can implement or utilize the various technologies described herein can use application programming interfaces (APIs), reusable controls, and the like. Such programs may be implemented in high-level procedures or object-oriented programming languages to communicate with computer systems. However, the program(s) may be implemented in combination or machine language as needed. In any case, the language can be a compiled or literal language, and combined with hardware implementations.

It should be understood that many functional units described in this specification can be implemented as one or more components, which is a term used to more specifically emphasize their implementation independence. For example, the component can be implemented as a package Hardware circuits containing traditional very large integrated (VLSI) circuits or gate arrays, off-the-shelf semiconductors (such as logic chips, transistors), or other discrete components. Components can also be implemented in programmable hardware devices, such as field-effect programmable gate arrays, programmable array logic, programmable logic devices, or the like.

The components can also be implemented in software executed by various types of processors. The identified components of the executable code may, for example, include one or more physical or logical blocks of computer instructions, which may be composed of, for example, objects, programs, or functions. However, the executable files of the identified components do not need to be physically located together, but can contain different instructions stored in different locations, which when logically combined together contain the component and achieve the stated purpose of the component .

Indeed, the components of the executable code can be a single instruction or many instructions, and can even be distributed across several different code segments, in different programs, and across several memory devices. Similarly, the operating data can be identified and shown in the component here, and may be embodied in any suitable form and composed in any suitable type of data structure. The operating data can be collected as a single data set, or can be distributed across different locations including different storage devices, and can only exist at least partially as electronic signals on the system or on the network. These components can be passive or active and include agents that are operable to perform the required functions.

References to "examples" throughout this specification mean that the specific features, structures, or characteristics described for the example are included in at least one embodiment of the present disclosure. Therefore, the term "in the instance" is used in each of this description The occurrences of are not necessarily all referring to the same embodiment.

As used herein, a plurality of items, structural elements, constituent elements, and/or materials may be presented in a common list for convenience. However, these lists should be interpreted as if the components of the list are individually identified as separate and unique components. Therefore, individual components of such a list should not be interpreted as de facto equivalents of any other components of the same list based on their presentation in a common group without indication to the contrary. In addition, various embodiments and examples of the present disclosure may be mentioned here along with alternatives to various components thereof. It is understood that such embodiments, examples, and substitutes are not interpreted as de facto equivalents to each other, but are interpreted as individual and autonomous expressions of this disclosure.

Although the foregoing has been described in some details for clarity, it will be obvious that certain changes and modifications can be made without departing from the principle. It should be noted that there are many alternative ways to implement both the programs and equipment described here. Therefore, the present embodiment is regarded as illustrative and non-limiting.

Those familiar with the art will understand that many changes can be made to the details of the above embodiments without departing from the implicit principles of the present disclosure. Therefore, the scope of this disclosure should only be determined by the scope of the following patent applications.