TRANSCEIVER POINT BEAM FAILURE RECOVERY

Embodiments of the present disclosure relate to devices, methods, apparatuses and computer readable storage media of TRP beam failure recovery. The method comprises determining a set of failed cells associated with the first device based on a beam failure detection; and generating a beam failure report indicating respective one or more failure detection resource sets associated with at least a portion of the set of failed cells. In this way, the UE may determine the information included in the BFR MAC CE in a case where the UL grant is not enough to include all the information for the failed serving cells or the BFR MAC to be transmitted on the MSG3 or MSGA in a CBRA procedure on the SpCell.

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular to devices, methods, apparatuses and computer readable storage media of Transceiver Point (TRP) beam failure recovery.

BACKGROUND

Currently, the support for multi-TRP beam failure recovery has been discussed. For example, the enhancement on support for multi-TRP deployment may comprises identifying and specifying features to improve reliability and robustness for channels other than PDSCH by using multi-TRP and/or multi-panel.

To enhance the current beam failure detection procedure to cover the multi-TRP operation, it has been agreed that multi-TRP Beam Failure Report (BFR) may use Secondary Cell (SCell) BFR as a baseline, i.e., a User Equipment (UE) can be configured with more than one Beam Failure Detection Resource Set (BFD-RS) sets per serving cell.

SUMMARY

In general, example embodiments of the present disclosure provide a solution of TRP beam failure recovery.

In a first aspect, there is provided a method. The method comprises determining a set of failed cells associated with the first device based on a beam failure detection; and generating a beam failure report indicating respective one or more failure detection resource sets associated with at least a portion of the set of failed cells.

In a second aspect, there is provided a first device. The first device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device at least to perform the method according to the first aspect.

In a third aspect, there is provided an apparatus comprising means for determining a set of failed cells associated with the first device based on a beam failure detection; and means for generating a beam failure report indicating respective one or more failure detection resource sets associated with at least a portion of the set of failed cells.

In a fourth aspect, there is provided a computer readable medium having a computer program stored thereon which, when executed by at least one processor of a device, causes the device to carry out the method according to the first aspect.

Other features and advantages of the embodiments of the present disclosure will also be apparent from the following description of specific embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of embodiments of the disclosure.

DETAILED DESCRIPTION

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish functionalities of various elements. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NR Next Generation NodeB (gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology. A RAN split architecture comprises a gNB-CU (Centralized unit, hosting RRC, SDAP and PDCP) controlling a plurality of gNB-DUs (Distributed unit, hosting RLC, MAC and PHY). A relay node may correspond to DU a portion of the IAB node.

Although functionalities described herein can be performed, in various example embodiments, in a fixed and/or a wireless network node, in other example embodiments, functionalities may be implemented in a user equipment apparatus (such as a cell phone or tablet computer or laptop computer or desktop computer or mobile IoT device or fixed IoT device). This user equipment apparatus can, for example, be furnished with corresponding capabilities as described in connection with the fixed and/or the wireless network node(s), as appropriate. The user equipment apparatus may be the user equipment and/or or a control device, such as a chipset or processor, configured to control the user equipment when installed therein. Examples of such functionalities include the bootstrapping server function and/or the home subscriber server, which may be implemented in the user equipment apparatus by providing the user equipment apparatus with software configured to cause the user equipment apparatus to perform from the point of view of these functions/nodes.

FIG.1shows an example communication network100in which embodiments of the present disclosure can be implemented. As shown inFIG.1, the communication network100may comprise a terminal device110(hereinafter may also be referred to as a UE110or a first device110). The communication network100may further comprise TRPs120-1and120-2, which may communicate with the terminal device110within the coverage of cells101and102, respectively. Hereinafter the TRP120-1may also be referred to as a first TRP120-1and the TRP120-2may also be referred to as a second TRP120-2. It is to be understood that TRPs120-1and120-2may comprise of one or more TRPs.

It is to be understood that the number of network devices and terminal devices shown inFIG.1is given for the purpose of illustration without suggesting any limitations. The communication network100may include any suitable number of network devices and terminal devices.

As described above, the enhancement on beam failure detection procedure to cover the multi-TRP operation has been discussed.

It has been agreed that the BFR information for failed TRP can be provisioned using a Media Access Control Control Element (MAC CE). A failure of a TRP (and TRP may refer to one or more TRPs) may be determined based on the failure of beam failure detection reference signals in beam failure detection reference signal set or a resource set. In some example embodiments, the failure detected on a TRP may refer to a failure detected on the reference signals associated with the TRP. However, it is to be understood that in any of the embodiments herein, the reference signals in one resource set (beam failure detection resources in a resource set) may be transmitted by one or more TRPs. In some embodiments, there may be one or more beam failure detection resource sets per each serving cell, which may be referred to as a Primary Cell (PCell) or a Secondary Cell (SCell). A Scheduling Request (SR) (or up to 2) can be configured for the UE and the UE may use the SR to indicate a failure of at least one of the TRPs (i.e., Beam Failure Detection Resource Sets (BDF-RSs)). As a response network device may schedule UE an Uplink (UL) grant for provision of a BFR MAC CE for recovering the TRP.

In any of the embodiments herein the ‘TRP’ and ‘a BDF-RS’ may be used inter-changeably.

In any of the embodiments herein the multi-TPR operation and beam failure recovery thereof may refer to intra-cell deployment or inter-cell deployment. In the inter-cell multi-TRP operation, the UE may be configured with at least one Control Resource Set (CORESET) that has active Transmission Configuration Indicator (TCI) State for Physical Downlink Control Channel (PDCCH) reception (i.e. the RS indicated by the active TCI state is used as reception assumption for the PDCCH) that is associated with and cell identifier (i.e., Physical Cell Identifier (PCI), or an index value associated with the PCI) different from the serving cell.

In some embodiments, the UE may be configured with inter-cell beam management operation where the UE may be configured to receive and transmit from/to from a cell with a different cell identifier than the serving cell while still being served by the UE's serving cell (i.e. the serving cell may not change same although UE is configured to receive/transmit signals/channels from cell with different cell identifier than serving cell).

The size of the UL grant is typically small and the network device may not have knowledge on the amount of information that the UE would need to send, if multiple cells associated with the UE have failed TRP. Thus, the UE may not be able to provide full MAC CE.

In addition, the BFR MAC CE for multi-TRP recovery can also be transmitted on any available UL grant without SR and the grant may not be sufficient to accommodate the full BFR MAC.

The BFR MAC CE may also be transmitted using Contention Based Random Access (CBRA). However, the grant size for Message A (MSGA)/Message 3 (MSG3) is typically set to very minimum. When the UE initiates BFR procedure using CBRA for Special Cell (SpCell) and intends to indicate the BFR MAC CE in the MSGA/MSG3 grant, even the truncated BFR MAC CE would not fit within the 56 bits MSGA/MSG3 grant when 4 octet bitmap is used. Hereinafter the Special Cell (SpCell) may comprise one of the Primary Cell (PCell) or Primary Secondary Cell (PSCell).

Based on the above-mentioned situation, it has been defined that the truncated BFR MAC CE may indicate the network device that the UE may transmit only a portion of the information in the MAC CE. Furthermore, it has also been defined that the UE may include as much data as possible for the UL while not exceeding the UL grant by maximizing the number of Secondary Cells (SCells) to be reported and including the in them ascending order (of the serving cell index/identifier).

The ascending order can be considered as feasible solution for the SCell BFR in Release 16, since all the SCells configured with BFR have similar failure detection in terms of number of BFD-RS sets. However, in Release 17, the UE may have configuration for TRP specific beam failure detection, i.e., such detection may be configured on serving cell basis and thus it is expected that following configurations can be supported for each serving cell configured for beam failure detection in Release 17, namely a serving cell is configured for TRP specific failure detection and both TRPs fail and a serving cell is not configured TRP specific failure but for legacy failure detection.

Based on the configuration, one serving cell may be configured with TRP specific failure while the other serving cell may be configured with cell level failure detection. In this situation, it may not be feasible to list the failed serving cells in ascending order as the failure situation may be different for each failed serving cell.

It is to be discussed how to determine the information that is included in the truncated BFR MAC CE for multi-TRP beam failure recovery when the UL grant cannot accommodate full information or in the BFR MAC CE for multi-TRP is transmitted on MSG3 or MSGA.

Therefore, the present disclosure provides solutions of TRP beam failure recovery. In this solution, the UE may determine a set of failed cells associated with the first device based on a beam failure detection. Furthermore, the UE may generate a beam failure report (such as beam failure recovery request) indicating respective resource sets associated with the set of failed cells. The respective resource sets may be corresponding to one or more transceiver points configured for respective one of failed cells in the set of failed cells. In this way, the UE may determine the information included in the BFR MAC CE in a case where the UL grant is not enough to include all the information for the failed serving cells or the BFR MAC to be transmitted on the MSG3 or MSGA in a CBRA procedure on the SpCell.

Principle and implementations of the present disclosure will be described in detail below with reference toFIG.2, which shows a flowchart of an example method200of TRP beam failure recovery according to some example embodiments of the present disclosure. The method200can be implemented at the UE110as shown inFIG.1. For the purpose of discussion, the method200will be described with reference toFIG.1.

In a beam failure recovery procedure, the UE may perform a Beam Failure Detection (BFD) for the serving cells of the UE110. At210, the UE110may determine a set of failed cells from the serving cells based on the result of the beam failure detection.

At220, the UE110may generate a beam failure report which may indicate respective one or more failure detection resource sets (BFD-RS sets) associated with at least a portion of the set of failed cells.

In some example embodiment, the BFD-RS sets may be identified based on an index associated with the BFD-RS set. In the beam failure recovery request (BFR MAC CE, beam failure report or the like), the failed BFD-RS set (index) may be indicated using a bit field with specific value (for example, ‘0’ for no failure and ‘1’ for failure or vice versa).

In some example embodiments, the octet containing the AC field indicates the associated BFD-RS set implicitly i.e. when two octets are included in the MAC CE, there is a respective containing the AC field for failed BFD-RS set. As an example, for the failed servCellIndex, the failed BFD-RS set with first index value is listed first in the MAC CE and the failed BFD-RS set with second index value is listed second in the MAC CE. In this way the octet position encodes the BFD-RS set index value and the octet containing the AC field is associated with respective BFD-RS set. In another example, if only one octet is present in the MAC CE, a bit field in the octet may indicate the failed BFD-RS set. Alternatively, in case only one octet is present the octet corresponds to the octet containing the AC filed that is associates to specific BFD-RS set index value (e.g. BFD-RS set with first value or second value).

In any of the example embodiments herein, the octet containing the AC field may not be limited to a byte (8 bits) and the information field to provide candidate beam information/beam failure recovery information associated with the failed BFD-RS set (or TRP) may have length of 2 octets or in general, N-bit length (N=1, 2, 3, 4 . . . bits).

In some example embodiments, the UE110may determine a respective first failed failure detection resource set for each of the set of failed cells and generate the BFR based on the determined first failed failure detection resource sets.

For example, in a case where the octets containing the Available Candidate (AC) field, if present, are included in ascending order based on the ServCellIndex and only single octet containing the AC field per serving cell is included, one bit in the octet containing the AC field may encode the failed BFD-RS set identifier. For example, if the TRP120-1and TRP120-2may be referred to as TRP 0 (BFD-RS set #0) and TRP 1 (BFD-RS set #1), the encoded failed BFD-RS set identifier may be 0 or 1.

In some example embodiments, the determined failed failure detection resource set(s) to be reported in the BFR may be selected based on the resource set containing the RS associated with lowest Control Resource Set (CORESET) index or contain the RS with lower identifier. As an example, if BFD-RS set #0 includes RS that is associated with a CORESET with index #0 and if BFD-RS #1 set includes RS that is associated with CORESET with index #1, the failure indication for BFD-RS set #0 is prioritized.

In some example embodiments, if one octet containing the AC field per failed serving cell is included in the BFR information, the UE may not include any further octets containing the AC field for any failed serving cell in the BFR information. As an example, if for some serving cell the both BFD-RS sets have failed (or more than one BFD-RS set has failed), UE includes only one octet containing the AC field corresponding to the one failed RS set.

In some example embodiments, if one octet containing the AC field per failed serving cell is included in the BFR information, UE determines to include the information on BFD-RS set with lower identifier value (e.g. in case there are 2 sets of BFD-RS with identifiers 0 and 1 and both sets have failed). In some example embodiments, if one octet containing the AC field per failed serving cell is included in the BFR information UE indicates the information on the BFD-RS set that is associated with the serving cell. As an example, in inter-cell multi-TRP and/or inter-cell beam management the BFD-RS set may be associated with a cell with a different identifier than serving cell i.e. UE performs beam failure detection on the serving cell and one another cell. The cell with different identifier than serving cell may be a portion of the serving cell configuration.

In some example embodiments, the UE110may determine a respective first failed failure detection resource set for each of the set of failed cells. If a subset of failed cells in the set of failed cells are detected with more than one failed failure detection resource sets, the UE110may determine a respective second failed failure detection resource set for at least a portion of the subset of failed cells. The determined second failed failure detection resource sets are different from the determined first failed failure detection resource sets. Then the UE110may generate the BFR based on the determined first and second failed failure detection resource sets.

For example, in a case where the octets containing the AC field, if present, are included in ascending order based on the ServCellIndex and single octet containing the AC field per serving cell is included and if at least serving cell has detected failure for more than one failed BFD-RS, the UE may include the second octet containing in the ascending order of serving cell index.

In this case, one candidate beam octet associated with one failed BFD-RS is listed first per serving cell. In this first round of included octets, one bit in the octet containing AC field may indicate the failed BFD-RS set associated with a corresponding TRP.

Then, if a portion of serving cells have been detected with more than one failed BFD-RS set, one bit may indicate whether the “other/another” failed BFD-RS set was included in the first round of included octets.

In some example embodiments, for each reported cell, one bit in the octet containing the AC field may indicate whether second byte (AC field octet) follows the first indicated octet containing the AC field.

In some example embodiments, the BFR information (such as the MAC CE) may also comprise one bit used the octet containing AC to indicate if one or both BFD-RS sets failed in the cell. This information may be present per serving cell that has been indicated with failure in the MAC CE.

In some example embodiments, the failure information of the BFD-RS set associated with lower CORESET index or with lowest CORESET index (associated in a manner e.g. that BFD-RS set includes the RS indicated by the activated TCI state for the CORESET) may be indicated in the first round of included octets. As an option, if in this case the BFD-RS set with lower index/lowest CORESET index has not failed, the AC bit may indicate “no candidate” and follows a bit indicating that no failure was detected for this BFD-RS set.

In some example embodiments, the failure information of the second BFD-RS set may be indicated after the failure information of the first BFD-RS set based on the available grant size. As an option, the failure information of the second BFD-RS set could be included in ascending/descending order of the serving cell ID. Alternatively or additionally, the failure information of SpCell or PUCCH SCell may be prioritized. As an example, if serving cells SCell1 and SCell2 fail (one or two BFD-RS set fail for the serving cells) and SCell1 is a PUCCH SCell (i.e. it has an uplink at least for PUCCH transmission) the failure information on SCell 1 is included with priority over SCell 2. As another example, all the failed BFD-RS sets (e.g., one or two) of SpCell are always prioritized over the failure information of other cell(s), like SCell(s).

In some example embodiments, UE may include two octets with AC field for the serving cell (for respective failed BFD-RS sets) if the cell is an SpCell (and both BFD-RS sets have failed). For any failed SCell that is indicated, UE may include only one octet with AC field.

In some example embodiments, the UE110may determine a respective first resource set for each of the set of failed cells and a respective second resource set for at least a portion of the set of failed cells if more than one TRPs are configured for respective one of failed cells. The UE110may generate the beam failure report based on the determined first and second resource sets.

For example, in a case where the octets containing the AC field, if present, are included in ascending order based on the ServCellIndex and two octets containing AC fields (or only one octet if the said ServCellIndex has one BFD-RS set) are included regardless of the failure status of the second TRP. In a case that two octets for a ServCellIndex cannot be included (e.g. due to size limitation i.e. the amount of information is already maximized) UE includes only one octet containing AC field. The included octet may be the octet containing the AC field for BFD-RS set with first value (or alternatively the set with second value). The one included octet may encode the index value of the failed BFD-RS set. Alternatively, in a case that two octets for a ServCellIndex cannot be included, both octets with AC field are omitted. In a case where both octets containing the AC field cannot be included, information of a failed ServCellIndex with one octet containing AC filed may be included.

In this case, a first BFD-RS set associated with one TRP may be included first and a second BFD-RS set associated with the other TRP may be included second per failed serving cell.

In some example embodiments, one bit in the octet containing the AC field may indicate whether the first and/or second BFD-RS set has failed or not.

In some example embodiments, the second octet containing AC field for the second BFD-RS set for any serving cell is included only after the first octet containing AC field has been encoded for all the failed serving cells. In this situation, in the first octet containing AC field, one bit may be used to indicate which BFD-RS set is indicated first. In the second octet containing AC field, one bit may be used to indicate if the second BFD-RS set also failed.

In some example embodiments, the second octet for the failed serving cells may be included per prioritization rules. For example, the second octet for the failed serving cells may be included based on serving cell ID in descending/ascending order. It is also possible that BFD-RS sets associated with certain type of failed cell may be included priority to other BFD-RS sets. For example, SpCell, PUCCH SCell or SCells with configured UL can be prioritized.

In some example embodiments, the UE110may determine a respective first failed failure detection resource set for at least a portion of the set of failed cells and generate the beam failure report based on the determined first failed failure detection resource sets. For example, in a case where the octets containing the AC field, if present, are included in ascending order based on the ServCellIndex and only single octet containing the AC field per serving cell is included, SCells with PUCCH may be prioritized over SCells without PUCCH.

In some example embodiments, in a case where the octets containing the AC field, if present, are included in ascending order based on the ServCellIndex and only octets containing the AC fields per serving cell is included for the cells that have failure of both TRPs or have been configured with one BFR-RS set only. In this case, as an option, the serving cells with multi-TRP BFR configuration have both candidate beam octets included. As another option, the serving cells with multi-TRP BFR (e.g. cells with more than one CORESETpoolindex values) configuration have one candidate beam octet included indicating failure of a BFD-RS set with lower set identifier.

In some example embodiment, the multi-TRP configuration may refer to cells configured with more than one CORESETpoolindex values.

In some example embodiment, the multi-TRP BFR configuration may refer to cells configured with more than one CORESETPoolIndex values and the BFD-RS sets are associated with the CORESETPoolindex values.

In some example embodiments, the field for indicating the failed cells in the BFR may indicate all the serving cells that have either BFD-RS set specific (one of the BFD-RS sets of a cell fail) or cell-specific (both BFD-RS sets fail, or both BFD-RS sets fail and no candidates available or cell is configured with only one BFD-RS set) beam failure detected.

In some example embodiments, the serving cell(s) with only cell-specific BFR are prioritized over the serving cells with multi-TRP configured when reporting truncated BFR. the field for indicating the failed cells may indicate only the cells reported since otherwise the network would not be able to identify the prioritized cells. The network knows there are other cell(s) failed that are not reported via a different LCID for truncated multi-TRP BFR than normal multi-TRP BFR, and as in legacy BFR for those cells remain triggered.

In some example embodiments, the generated BFR may be transmitted for failed SpCell in MSG 3/MSG A.

For example, the BFR MAC CE can be included in MSG 3/MSG A only in case both BFD-RS resource sets failed in SpCell or when the TRP linked to SpCell failed in case of inter-cell multi-TRP. Due to occurrence of RACH, the network may deduce from the BFR MAC CE in MSG3/MSGA already that both BFD-RS resource sets of SpCell have failed.

In some example embodiments, the BFD-RS set with lowest CORESET index is included in the AC octet if candidate is available. If no candidate available, the BFD-RS set with higher CORESET index may be included. In this case, one bit in the octet containing the AC field may encode the information of the failed TRP/BFD-RS index.

If there are no candidates available for either of the failed BFD-RS Sets, the bit in the octet containing AC field is set to 1 to indicate failure of BFD-RS resource set1and the AC field is set to indicate that no candidate is available. Therefore, the network may be indicated that no candidate from the candidate beam RS lists is available for either of the BFD-RS resource sets and the SSB selected for CBRA is the new candidate beam.

In some example embodiments, the BFR MAC CE may also comprise a Logical Channel Identification (LCID) identifying the MAC CE for multi-TRP BFR. The LCID may indicate whether the MAC CE is a truncated or non-truncated.

In some example embodiments, the LENGTH field may also be included in the BFR MAC CE in a case where the MAC CE is not a fixed size CE.

FIG.3shows an example of BFR according to some example embodiments of the present disclosure. As shown inFIG.3, the MAC CE structure300for the BFR may comprise a LCID field301, which may indicate whether the MAC CE is a truncated or non-truncated. The MAC CE structure300may also comprise a LENGTH field302, which may be included in case the MAC CE is not a fixed size CE.

The MAC CE structure300may also comprise a field indicating the failed cells303, which may also be referred to as serving cell index octet. The serving cell index octet may identify the failed serving cell when the corresponding bit is set to a value indicating that a failure is detected. For example, the bit field is set to 1 for failure and the bit field is set to 0 for non-failure. In some example embodiments, the field303could be 4 octets as well when the highest ServCellIndex of failed/reported serving cell is larger than 8.

As shown inFIG.3, a candidate beam octet per TRP (BFD-RS set) is shown and octets may be present per serving cell. It is to be understood that the MAC CE structure shown inFIG.3may be referred to as a non-limiting implementation example for multi-TRP BFR MAC CE.

In the MAC CE structure300ofFIG.3, two candidate beam information fields may be included for each serving cell. For example, candidate beam information fields304and305are included for a serving cell and candidate beam information fields306and3057are included for another serving cell.

In the candidate beam information fields, R1 field may be referred to as reserved bit and the AC field may be referred to as available candidate. The candidate RS index may be referred to as index of the identified candidate beam if suitable candidate is found.

In some example embodiments, the R1 bit may also be used to indicate whether the first beam has failed and R2 bit is used to indicate whether the second beam has failed.

In some example embodiments, the R1 bit may also be used to indicate whether the second TRP has beam failure. The second octet for the serving cell can be omitted if R1 indicates 0, which means the second TRP has not failed.

For a serving cell configured with only cell-specific BFR, R bit is reserved or set to 0, which means only one AC/candidate RS index octet for the serving cell.

In some example embodiments, an apparatus capable of performing the method200(for example, implemented at the first device110) may comprise means for performing the respective steps of the method200. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for determining a set of failed cells associated with the first device based on a beam failure detection; and means for generating a beam failure report indicating respective one or more failure detection resource sets associated with at least a portion of the set of failed cells.

FIG.4is a simplified block diagram of a device400that is suitable for implementing embodiments of the present disclosure. The device400may be provided to implement the communication device, for example the UE110as shown inFIG.1. As shown, the device400includes one or more processors410, one or more memories440coupled to the processor410, and one or more communication modules440coupled to the processor410.

The communication module440is for bidirectional communications. The communication module440has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module440may include at least one antenna.

A computer program430includes computer executable instructions that are executed by the associated processor410. The program430may be stored in the ROM420. The processor410may perform any suitable actions and processing by loading the program430into the RAM420.

The embodiments of the present disclosure may be implemented by means of the program430so that the device400may perform any process of the disclosure as discussed with reference toFIGS.2to3. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some example embodiments, the program430may be tangibly contained in a computer readable medium which may be included in the device400(such as in the memory420) or other storage devices that are accessible by the device400. The device400may load the program430from the computer readable medium to the RAM422for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like.FIG.5shows an example of the computer readable medium500in form of CD or DVD. The computer readable medium has the program430stored thereon.