How and When we will construct a RRC paging message with multiple paging records?

Question

When we will construct a RRC paging message with multiple paging records?
In which scenario I need to construct a RRC paging message message with multiple paging records.Suppose we have 10 UEs in idle mode and DL data notification is comming for 5 UEs at the same time,then how mme will send S1AP paging message(i.e one by one for each UE or all the message at once).If ENB is receiving all the four S1AP paging message then how RRC has to process the S1AP paging messages and how it should construct the RRC paging message (i.e whether it should send one paging record for one pcch message or it should send multiple records in one PCCH message?if multiple records then how to send the UE_ids to MAC and RLC?).

Answer 1

Based on the my understanding please find my inputs over this question.

There are two important terms used associated with the paging procedure. Those terms are paging frame and paging occasion.
Paging Frame is a radio frame which may have one or more paging occasions. And paging occasions are the sub frames of the paging frame used to send paging message.

Multiple UEs within a cell may have same drx cycle. And each UE which is in IDLE mode wakes up and check for its message. So if multiple UEs have same drx cycle then multiple paging records for the those UEs shall be included in the same paging message.

For the calculation of paging frame and paging occasion, please refer the following link:
http://www.sharetechnote.com/html/Paging_LTE.html

Comments

Thanks for your answer but my question is about the RRC paging message(i.e implementation perspective ).At a time RRC cannot process the multiple S1AP paging messages.So according to me RRC can proces only one S1AP pagin message at a time(i.e within 1ms ) and can construct RRC paging mesage with only one paging record.So where we are including multiple paging records(Think  from mme side and rrc side implementation).Correct me if my understanding and thinking is wrong.

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Agreed. EnodeB may receive S1-AP paging messages per UE separately but based on DRX cycles of different UEs, eNodeb groups multiple paging messages for different UEs within a single rrc paging message. Please go through the concept of paging frames and paging occasions in details.

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Agreed.DRX cycles will be equal for all UE within a cell.PF and PO will be varied on the basis of UEid given by mme.Now my question is whether RRC need to buffer all  the S1AP paging messages and club them in one RRC paging message whose UEID is same?(i.e from design perspective)if buffering is to be done then how many messages, RRC should buffer?

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MME guards the paging procedure by running the timer T3413. The value of this timer is configurable. If MME receives NAS response (either Service Request or Extended Service Request) message from the UE, MME stops timer T3413.  And If timer expires, MME re-sends the S1-AP paging message for a particular UE.

From the RRC layer perspective, Maximum of 16 paging records can be send over the paging channel at a particular paging occasion.  I don't know what the eNodeB will do for the rest of S1-AP paging messages. Usually, eNodeB will try to send buffered rrc messages in next paging occasions. I will check with my friends in my organization and will update you.

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Thanks for your answer,please let me know the answer as soon as possible.