tag:blogger.com,1999:blog-1329449351744515518.post2766775625119510340..comments2023-09-16T01:28:38.178-07:00Comments on Wired n Wireless: LTE Tidbits IVSantosh Dornalhttp://www.blogger.com/profile/08888256274707899999noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-1329449351744515518.post-69806596312852926952010-06-15T00:20:42.315-07:002010-06-15T00:20:42.315-07:00Exactly! Now spread the word! :-)Exactly! Now spread the word! :-)Santosh Dornalhttps://www.blogger.com/profile/08888256274707899999noreply@blogger.comtag:blogger.com,1999:blog-1329449351744515518.post-65605323699464183522010-06-15T00:19:25.445-07:002010-06-15T00:19:25.445-07:00as per the discussions in "Spec Ambihuity&quo...as per the discussions in "Spec Ambihuity" section, I have some comments reg the FAQ-1....<br /><br />UE IDLE mode, neither SGW nor the eNB need to know the details of each other as no data would be flowing.<br /><br />UE CONNECTED mode, no element would be changed if TAU is initiated (user not moving), if user is moving and any change is there, handover will happen always before TAU.<br /><br />I hope this time I found it right.Asimanandanoreply@blogger.comtag:blogger.com,1999:blog-1329449351744515518.post-25635697563345049692010-06-14T22:42:08.107-07:002010-06-14T22:42:08.107-07:00eNB FTEID is sent in CSReq only if X2 HO with SGW ...eNB FTEID is sent in CSReq only if X2 HO with SGW change is in progress. Else there is no way MME will know about eNB FTEID untill and unless eNB sends them to it. <br /><br />Also standalone TAU procedure can be initiated by UE in Idle. Idle mode TAU can relocate SGW and also eNB as both SGW and eNB are freshly creating the bearers. <br /><br />One thing to understand here is, when UE is moving<br />1. A handover will occur if UE is in ECM Connected/RRC Connected mode<br />2. A UE will initiate TAU to let network know of its position in RRC Idle/ECM Idle modeSantosh Dornalhttps://www.blogger.com/profile/08888256274707899999noreply@blogger.comtag:blogger.com,1999:blog-1329449351744515518.post-11182632292163575212010-06-14T06:58:41.248-07:002010-06-14T06:58:41.248-07:00Regarding FAQ 1 :
I think the CSR contains the eN...Regarding FAQ 1 :<br /><br />I think the CSR contains the eNB IP and TEID details towards the SGW and thus SGW comes to know about eNB details.<br /><br />As per 23.401, "If the new MME selected a new Serving GW it sends a Create Session Request (IMSI, bearer contexts, MME Address and TEID, Type, the Protocol Type over S5/S8, RAT type) message to the selected new Serving GW.". <br /><br />I think the bearer context carries the eNB IP and TEID details (in S1-U eNodeB F-TEID IE), though I am not too sure about this.<br /><br />Now when the UE is in IDLE mode, there is no need to let the eNB know about the SGW IP and TEID details (as there will be no data flow in IDLE mode). When user is in CONNECTED mode, the TAU happens after a handover normally and handover procedure is responsible to let eNB know about the SGW IP and TEID details.<br /><br />Let me know if the above is correct.Asimanandanoreply@blogger.com