关于上发的detachrequest的原因

ue上发的  detach request的信令如下，此时服务小区RSRP良好，请问具体原因是什么？

Detach Request

Security header type: (2) Integrity protected and ciphered 

protocol_discriminator: EPS Mobility Management

Message authentication code: 0xd31a030 

Sequence number: 11 

Security header type: (0) Plain NAS message, not security protected 

protocol_discriminator: (7) EPS mobility management messages 

NAS EPS Mobility Management Message Type: (0x45) Detach request 

Type of security context flag (TSC): (0) Native security context 

NAS key set identifier: (1) 

Switch off: (1) Switch off 

Detach Type: (1) EPS detach 

EPS mobile identity - GUTI or IMSI

Length: 11 octets

odd/even indic: 0

Type of identity: (6) GUTI 

Mobile Country Code (MCC): (460) China (People's Republic of) 

Mobile Network Code (MNC): (00) China Mobile  

MME Group ID: 418

MME Code: 154

M-TMSI: 0xc81c3884