Reference point between RAN 120A and S-GW 230 for the
per bearer user plane tunneling and inter-gNodeB path
switching during handover
S5
Provides user plane tunneling and tunnel management
between S-GW 230 and P-GW 235. It is used for S-GW
relocation due to UE mobility and if the S-GW 230 needs to
connect to a non-collocated P-GW for the required PDN
connectivity.
S8
Inter-PLMN reference point providing user and control
plane between the S-GW 230 in a Visited Public Land
Mobile Network (VPLMN) and the P-GW 235 in a Home
Public Land Mobile Newtork (HPLMN). S8 is the inter-
PLMN variant of S5. P-GW 235 is shown as being the same
Public Land Mobile Network (PLMN) as S-GW 230 in FIG.
1B so only the S5 interface may apply in FIG. 1B. But the S8
interface would apply if P-GW 235 was located in a different
PLMN.
S11
Reference point between MME 215 and S-GW 230.
SGi
Reference point between the P-GW 235 and a packet data
network (PDN), shown in FIG. 1B as the Internet 175. The
PDN may be an operator external public or private packet
data network or an intra-operator packet data network (e.g.,