ok I tried setting m.rpdu to '41544341542b43474d49' however m.dispatch() return false, the log is:
2017-05-23_09:10:21.073131 <ybts-mm:ALL> Added UE (0x7fa98c002740) TMSI=007b0001 IMSI=234101713996691 [0x107b360]
2017-05-23_09:10:21.073143 <ybts:INFO> MT SMS 'ybts/sms/1' to (0x7fa98c002740) TMSI=007b0001 IMSI=234101713996691
2017-05-23_09:10:21.073164 <ybts-signalling:INFO> Sending [0x107af80]
-----
Primitive: StartPaging
Info: 1
<StartPaging>
<identity>TMSI007b0001</identity>
<imsi>234101713996691</imsi>
</StartPaging>
-----
2017-05-23_09:10:21.073177 <ybts:ALL> Started paging TMSI007b0001
2017-05-23_09:10:21.461247 <gsmtrx:INFO> ARFCN[0]: Slot 0. Receiver clipping 1.90356 dB (FN=36846) count=5 [0x7fa98800fc50]
2017-05-23_09:10:21.461538 <gsmtrx:ALL> Handling command 'CMD 0 NOHANDOVER 0' arfcn=0 [0x7fa988008da0]
2017-05-23_09:10:21.461558 <gsmtrx:ALL> Command 'CMD 0 NOHANDOVER 0' (ARFCN=0) RSP '0'
2017-05-23_09:10:21.461625 <gsmtrx:ALL> Handling command 'CMD 0 NOHANDOVER 0' arfcn=0 [0x7fa988008da0]
2017-05-23_09:10:21.461634 <gsmtrx:ALL> Command 'CMD 0 NOHANDOVER 0' (ARFCN=0) RSP '0'
2017-05-23_09:10:21.770979 <ybts-signalling:INFO> Received [0x107af80]
-----
Primitive: PhysicalInfo
Info: 0
Connection: 3
<PhysicalInfo>TA=0 TE=2.000 UpRSSI=1 TxPwr=33 DnRSSIdBm=-84 time=1495530621.474</PhysicalInfo>
-----
2017-05-23_09:10:21.771048 <ybts-signalling:INFO> Received [0x107af80]
-----
Primitive: L3Message
Info: 0
Connection: 3
<RRM>
<SkipIndicator>0</SkipIndicator>
<Message type="PagingResponse">
<CipheringKeySequenceNumber>no-key/reserved</CipheringKeySequenceNumber>
<MobileStationClassmark2>
<RFPowerCapability>class4</RFPowerCapability>
<RevisionLevel>GSM-phase2</RevisionLevel>
<SSScreeningIndicator>ellipsis-notation-and-phase2-error-handling</SSScreeningIndicator>
<Flags>ES-IND,E-GSM-and-R-GSM-support,MT-sms-point-to-point-capability,pseudo-sync-capability,A5/3-support,CMSP-support,LCS-VA-support,CM3-support</Flags>
</MobileStationClassmark2>
<MobileIdentity>
<TMSI>007b0001</TMSI>
</MobileIdentity>
</Message>
</RRM>
-----
2017-05-23_09:10:21.771061 <ybts-signalling:ALL> Added connection (0x7fa9940023b0,3) [0x107af80]
2017-05-23_09:10:21.771067 <ybts-mm:ALL> PagingResponse with TMSI=007b0001 conn=3 [0x107b360]
2017-05-23_09:10:21.771079 <ybts-signalling:INFO> Sending [0x107af80]
-----
Primitive: StopPaging
Info: 0
<StopPaging>
<identity>TMSI007b0001</identity>
</StopPaging>
-----
2017-05-23_09:10:21.771088 <ybts:ALL> Stopped paging TMSI007b0001
2017-05-23_09:10:21.771093 <ybts-signalling:ALL> Connection 3 set UE (0x7fa98c002740) TMSI=007b0001 IMSI=234101713996691 [0x7fa9940023b0]
2017-05-23_09:10:21.771100 <ybts-signalling:INFO> Sending [0x107af80]
-----
Primitive: EstablishSAPI
Info: 3
Connection: 3
-----
2017-05-23_09:10:22.006355 <ybts-signalling:INFO> Received [0x107af80]
-----
Primitive: PhysicalInfo
Info: 0
Connection: 3
<PhysicalInfo>TA=0 TE=2.000 UpRSSI=1 TxPwr=33 DnRSSIdBm=-84 time=1495530621.474</PhysicalInfo>
-----
2017-05-23_09:10:22.467595 <gsmtrx:INFO> ARFCN[0]: Slot 0. Receiver clipping 1.71572 dB (FN=37064) count=18 [0x7fa98800fc50]
2017-05-23_09:10:22.492632 <ybts-signalling:INFO> Received [0x107af80]
-----
Primitive: EstablishSAPI
Info: 3
Connection: 3
-----
2017-05-23_09:10:22.492656 <ybts-signalling:ALL> Connection 3 sapi establish 3 state 0x09 [0x107af80]
2017-05-23_09:10:22.492687 <ybts-signalling:INFO> Sending [0x107af80]
-----
Primitive: L3Message
Info: 3
Connection: 3
<SMS>
<TID TIFlag="false">0</TID>
<Message type="CP-Data">
<RPDU>41544341542b43474d49</RPDU>
</Message>
</SMS>
-----
2017-05-23_09:10:22.492707 <ybts:ALL> MT SMS 'ybts/sms/1' to (0x7fa98c002740) TMSI=007b0001 IMSI=234101713996691 sent on conn 3
2017-05-23_09:10:22.958063 <ybts-signalling:INFO> Received [0x107af80]
-----
Primitive: PhysicalInfo
Info: 0
Connection: 3
<PhysicalInfo>TA=2 TE=0.000 UpRSSI=1 TxPwr=33 DnRSSIdBm=-84 time=1495530622.463</PhysicalInfo>
-----
2017-05-23_09:10:22.958112 <ybts-signalling:INFO> Received [0x107af80]
-----
Primitive: L3Message
Info: 3
Connection: 3
<SMS>
<TID TIFlag="true">0</TID>
<Message type="CP-Ack"/>
</SMS>
-----
2017-05-23_09:10:22.958142 <ybts:ALL> SMS CP-ACK conn=3 callRef=0 tiFlag=true
2017-05-23_09:10:23.200404 <ybts-signalling:INFO> Received [0x107af80]
-----
Primitive: PhysicalInfo
Info: 0
Connection: 3
<PhysicalInfo>TA=2 TE=0.000 UpRSSI=1 TxPwr=27 DnRSSIdBm=-84 time=1495530622.463</PhysicalInfo>
-----
2017-05-23_09:10:23.200457 <ybts-signalling:INFO> Received [0x107af80]
-----
Primitive: L3Message
Info: 3
Connection: 3
<SMS>
<TID TIFlag="true">0</TID>
<Message type="CP-Data">
<RPDU enc="hex">04540160</RPDU>
</Message>
</SMS>
-----
2017-05-23_09:10:23.200477 <ybts:ALL> MT SMS 'ybts/sms/1' to (0x7fa98c002740) TMSI=007b0001 IMSI=234101713996691 responded
2017-05-23_09:10:23.200495 <ybts-signalling:INFO> Sending [0x107af80]
-----
Primitive: L3Message
Info: 3
Connection: 3
<SMS>
<TID TIFlag="false">0</TID>
<Message type="CP-Ack"/>
</SMS>
-----
2017-05-23_09:10:23.205598 <ybts:INFO> MT SMS 'ybts/sms/1' to (0x7fa98c002740) TMSI=007b0001 IMSI=234101713996691 failed reason='' RPDU=04540160