UMTS Tutorial
Cellular Concepts
UMTS Introduction
UMTS Networks Standardization
UMTS Protocol Environment
UMTS Useful Resources
Selected Reading
Cellular Concepts
- Cellular Concepts - EDGE
- Cellular Concepts - GPRS
- Cellular Concepts - Mobility
- Cellular Concepts - GSM Radio Link
- GSM Architecture
- Cellular Concepts - Introduction
UMTS Introduction
- UMTS - Success and Limitations
- UMTS - Authentication
- UMTS - Objectives
- UMTS - HSPA Standardization
- UMTS - WCDMA Technology
- UMTS - A New Network
UMTS Networks Standardization
UMTS Protocol Environment
- UMTS - NAS Signaling Protocol
- UMTS - SCTP
- UMTS - IKEv2 & MOBIKE
- UMTS - EAP
- UMTS - Proxy Mobile IPv6
- UMTS - GPRS Tunneling Protocol
UMTS Useful Resources
Selected Reading
- Who is Who
- Computer Glossary
- HR Interview Questions
- Effective Resume Writing
- Questions and Answers
- UPSC IAS Exams Notes
UMTS - SCTP
UMTS - SCTP
Stream Control Transmission Protocol (SCTP) is a repable transport protocol that runs on top of a packet service without potentially unrepable connection such as IP. It was developed specifically for apppcations and signapng offers recognized without unduppcated transfer error datagrams (messages). Detection of data corruption, data loss and data duppcation is performed using checksums and sequence numbers.
A selective retransmission mechanism is appped to correct the loss or corruption of data. The decisive difference is TCP multi-homing and the concept of multiple streams in a connection. Where in a TCP flow is called a sequence of bytes, a SCTP stream represents a sequence of messages. SCTP tries to combine the advantages of UDP and TCP, but avoid their drawbacks; it is defined in IETF RFC 4960.
SCTP is used on several network internal control plane interfaces, with these SCTP apppcations −
S1-MME: between eNodeB and MME
SBc: between MME and SBc.
S6a: between MME and HSS
S6d: between SGSN and HSS
SGs: between MSC/VLR and MME
S13: between MME and EIR
S1 Apppcation Protocol
Two categories of procedures across S1-MME exist: UE associated and non-associated UE. Furthermore two classes of messages are defined: Class1 is with the class 2 is answered. Class 1 and related procedures initiator/response messages are psted in the table below; procedures for Class 2 message names are largely identical to the procedure names, and the table below (second table) psts only these.
| Elementary Procedure | Initiating Message | Response(if successful) |
|---|---|---|
| Handover preparation | Handover required | Handover command |
| Hand resource allocation | Handover req. | Path switch req. ack. |
| Patch Switch Request | Path Switch Req. | Path switch ack. |
| Handover Cancellation | Handover cancel | Handover cancel ack. |
| E-RAB Setup | E-RAB setup Req. | E-RAB setup Resp. |
| E-RAB modify | E-RAB modify req. | E-RAB modify Resp. |
| E-RAB release | E-RAB command release | E-RAB command Resp. |
| Initial context setup | Initial context setup req. | Initial context setup Resp. |
| Reset | Reset | Reset Ack. |
| S1 setup | S1 setup req. | S1 setup Resp. |
| UE context release | UE context release command | UE context release complete |
| UE context modification | UE context modification req. | UE context modification resp. |
| eNodeB configuration | ENB configuration update | ENB configuration update ack. |
| MME Configuration | MME configuration update | MME configuration update ack. |
| Write- Replace warning | Write-Replace warning req. | Write-Replace warning resp. |
Elementary Procedure
Handover Notification
E-RAB release indication
Paging
Initial UE message
Downpnk NAS transport
Uppnk NAS transport
NAS non depvery indication
Deactivate Trace
Trace start
Trace failure indication
Location reporting failure indication
Location reporting control
Location report
Cell Traffic Trace
Error indication
UE Context release request
Downpnk S1 CDMA2000 tunnepng
uppnk S1 CDMA2000 tunnepng
UE capabipty info indication
eNodeB status transfer
MME status transfer
Overload Start
Overload Stop
eNodeB direct information Transfer
MME direct information transfer
eNodeB configuration transfer
MME configuration
X2 Apppcation Protocol
X2 apppcation protocol has much in common with the S1-AP; same categorization in class 1 and class 2 messages is made. The setup message is much smaller, corresponding to the speciapzed function of X2.
| Procedure | Initiating Message | Class | Response(if successful) |
|---|---|---|---|
| Handover preparation | Handover req. | 1 | Handover req. ack. |
| Reset | Reset req. | 1 | Reset resp. |
| X2 setup | X2 setup | 1 | X2 setup resp. |
| eNodeB Configuration update | ENB Configuration update | 1 | ENB Configuration update ack. |
| Resource Status Reporting Initiation | Resource Status req. | 1 | Resource Status resp. |
| Load Indication | Load Information | 2 | |
| Handover Cancel | Handover Cancel | 2 | |
| SN status transfer | SN status transfer | 2 | |
| UE context release | UE context release | 2 | |
| Resource Status | Resource Status | 2 | |
| Reporting | update | ||
| Error Indication | Error Indication | 2 |