import message sequence charts (ladder diagrams) for RUA/RANAP/NAS
diff --git a/doc/hnb_cs_mt_sms.msc b/doc/hnb_cs_mt_sms.msc
new file mode 100644
index 0000000..8a1b808
--- /dev/null
+++ b/doc/hnb_cs_mt_sms.msc
@@ -0,0 +1,67 @@
+msc {
+ hscale = "3";
+ ue,hnb,hnbgw,cn;
+
+ cn box cn [ label = "subscriber A send a SMS; signalling arrives at CN" ];
+
+ cn => hnbgw [ label = "SCCP UDT (RANAP Paging Command)" ];
+ hnbgw => hnb [ label = "RUA ConnectionlessTransfer (RANAP Paging Command)" ];
+ hnb => ue [ label = "RRC Paging" ];
+
+ ue box hnb [ label = "Radio Channel Establishment" ];
+ ue => hnb [ label = "RRC (CM PAGING RESP)" ] ;
+ hnb => hnbgw [ label = "RUA CONNECT (RANAP Initial UE Msg (CM PAGING RESP))" ];
+ hnbgw => cn [ label = "SCCP CR (RANAP Initial UE Msg (CM PAGING RESP))" ];
+ cn >> hnbgw [ label = "SCCP CC" ];
+
+ --- [ label = "Optional retrieval of IMSI (if not given in CM or retrived from VLR by TMSI)" ];
+ cn => hnbgw [ label = "SCCP DT1 (RANAP DirectTransfer (MM IDENTITY REQ))" ];
+ hnbgw => hnb [ label = "RUA DT (RANAP DirectTransfer (MM IDENTITY REQ))" ];
+ hnb => ue [ label = "RRC (MM IDENTITY REQ)" ];
+ ue >> hnb [ label = "RRC (MM IDENTITY RESP)" ];
+ hnb >> hnbgw [ label = "RUA DT (RANAP DirectTransfer (MM IDENTITY RESP))" ];
+ hnbgw >> cn [ label = "SCCP DT1 (RANAP DirectTransfer (MM IDENTITY RESP))" ];
+
+ --- [ label = "Mandatory activation of Integrity Protection" ];
+ cn => hnbgw [ label = "SCCP DT1 (RANAP SecurityModeCommand (IK))" ];
+ hnbgw => hnb [ label = "RUA DT (RANAP SecurityModeCommand (IK))" ];
+ hnb >> hnbgw [ label = "RUA DT (RANAP SecurityModeResponse (IK))" ];
+ hnbgw >> cn [ label = "SCCP DT1 (RANAP SecurityModeResponse (IK))" ];
+
+ cn => hnbgw [ label = "SCCP DT1 (RANAP CommonID)" ];
+ hnbgw => hnb [ label = "RUA DT (RANAP CommonID)" ];
+
+ --- [ label = "Optional Authentication" ];
+ cn => hnbgw [ label = "SCCP DT1 (RANAP DirectTransfer (MM AUTH REQ))" ];
+ hnbgw => hnb [ label = "RUA DT (RANAP DirectTransfer (MM AUTH REQ))" ];
+ hnb => ue [ label = "RRC (MM AUTH REQ)" ];
+ ue >> hnb [ label = "RRC (MM AUTH RESP)" ];
+ hnb >> hnbgw [ label = "RUA DT (RANAP DirectTransfer (MM AUTH RESP))" ];
+ hnbgw >> cn [ label = "SCCP DT1 (RANAP DirectTransfer (MM AUTH RESP))" ];
+
+ --- [ label = "Optional activation of Encryption" ];
+ cn => hnbgw [ label = "SCCP DT1 (RANAP SecurityModeCommand (IK+CK))" ];
+ hnbgw => hnb [ label = "RUA DT (RANAP SecurityModeCommand (IK+CK))" ];
+ hnb >> hnbgw [ label = "RUA DT (RANAP SecurityModeResponse (IK+CK))" ];
+ hnbgw >> cn [ label = "SCCP DT1 (RANAP SecurityModeResponse (IK+CK))" ];
+
+ cn => hnbgw [ label = "SCCP DT1 (RANAP DirectTransfer (CP-DATA (RP-DATA (SMS DELIVER))))" ];
+ hnbgw => hnb [ label = "RUA DT (RANAP DirectTransfer (CP-DATA (RP-DATA (SMS DELIVER))))" ];
+ hnb => ue [ label = "RRC (CP-DATA (RP-DATA (SMS DELIVER)))" ];
+
+ ue => hnb [ label = "RRC (CP-ACK)" ];
+ hnb => hnbgw [ label = "RUA DT (RANAP DirectTransfer (CP-ACK))" ];
+ hnbgw => cn [ label = "SCCP DT1 (RANAP DirectTransfer (CP-ACK))" ];
+
+ ue => hnb [ label = "RRC (CP-DATA (RP-ACK)" ];
+ hnb => hnbgw [ label = "RUA DT (RANAP DirectTransfer (CP-DATA (RP-ACK)))" ];
+ hnbgw => cn [ label = "SCCP DT1 (RANAP DirectTransfer (CP-DTA (RP-ACK)))" ];
+
+ cn => hnbgw [ label = "SCCP DT1 (RANAP DirectTransfer (CP-ACK))" ];
+ hnbgw => hnb [ label = "RUA DT (RANAP DirectTransfer (CP-ACK))" ];
+ hnb => ue [ label = "RRC (CP-ACK)" ];
+
+ cn box cn [ label = "MAP MT Forward SM to GMSC/SMSC" ];
+
+ cn box hnb [ label = "RAB Release or Iu Release" ];
+}