LTE: What is SPID (Subscriber Profile Id) and what significance it has ?

Question

I saw S1-AP "Initial Context Setup Request" message which may carry Subscriber Profile ID IE (optional). I want to know about this.

Answer 1

Hi Harshita ,SPID is received by eNB via s1 interface is an index referring to user information.The information is ue specific and applies to all RB's.The index is mapped by the enb to locally defined configuration in order to apply specific rrm strategies(eg define rrc_idle mode priorities and control inter-rat/inter freq HO in rrc_connected mode)

SPID RANGES values 1-128->operator specific spid values
129-256-reference values

SPID=256
CONFIGURATION PARAMETERS VALUE
E-UTRAN CARRIERS PRIORITY HIGH
UTRAN CARRIERS PRIORITY MEDIUM
GERAN CARRIERS PRIORITY LOW

Hope this helps u

Answer 2

SPID can be used to take rrm decisions (like Handover or Cell Reselection) rather than using the regular method. The regular method of Handover or Cell Reselection is usually based on Power levels / SINR and/or RSRP, RSRQ thresholds etc.

Whereas the subscriber profile id approach is grouping users into different cells or frequencies based on subscription information. This will be typically useful if an operator has multiple frequencies and based on the subscription information of the users, you may want to camp him on one cell or the other.