Course Overview
Asynchronous Transfer Mode (ATM) is a powerful layer 2 switching technology that can offer flexible mixed-media transport with mixed quality of service. Support of ATM within the UTRAN is mandatory at Release 99 and Release 4 of the UMTS specification. It is also commonly found supporting IP in the core network and is likely to remain in wide use post Release 4.
This course covers the principles of ATM operation, its structure, operational practicalities and applications, focusing on the features that are relevant to its application in UMTS. Starting with an examination of the UTRAN interface requirements, the course develops this into a detailed description of ATM virtual circuits. Next are descriptions of the ATM layer structure and the ATM Adaptation Layers 2 and 5. Then traffic management strategies are covered, along with ATM signalling protocols. The course ends with an explanation of how ATM is applied on the UTRAN interfaces, including signalling flow examples.
Audience
This course is primarily designed for engineers working for equipment manufacturers and for network operators who are involved in equipment design, manufacturing, transmission planning, network optimization, strategy determination or deployment of UMTS technology. Some will find that this course satisfies their complete requirements, while for others it will provide a stepping stone to further research and study based on primary material and related courses. This course is also very useful for engineers and scientists working in areas related to UMTS. This includes equipment commissioning, equipment design, Government security or forensic work, service developers, support staff and those in technical management roles.
Skills Gained
On completion of this course the student will be able to:
- justify the use of ATM within the UTRAN
- identify the two generic forms of ATM virtual circuit, Switched Virtual Circuit (SVC) and Permanent Virtual Circuit (PVC), and relate them to UTRAN interfaces
- describe the layers and planes associated with the ATM model
- explain the role of the physical layer, including its sublayers, as it relates to ATM
- describe the cell structure and headers used in the ATM layer
- describe the functionality of ATM Adaptation Layers 2 and 5, including their sublayers
- explain the functions of traffic control and congestion control
- explain the functions of connection admission control and usage parameter control
- describe traffic parameters identified by the ITU-T and state how these map to ATM transfer capabilities
- describe the functions of ATM signalling protocols and explain how they control VCs within the UTRAN
- describe the protocol stacks on the UTRAN interfaces and their respective AAL processes
Prerequisites
This course assumes a good working knowledge of transmission and switching principles along with a general understanding of cellular network architecture and the UTRAN. This can be obtained from our Introduction to Telecoms and UMTS System Overview courses.
Course Outline
Introduction to UMTS
- UMTS elements and interfaces
- ATM interfaces
- UTRAN protocol structure
- Why ATM?
- Service capabilities
- Efficient use of the resource
- QoS requirements
- UMTS bit rates
- Factors limiting bit rate
- UMTS teleservices
- Internet access
- Air interface modes of operation
- UMTS channel types and functions
- Transport formats
- Types of RNC
Overview of ATM
- Switching networks
- Circuit switching and packet switching
- Disadvantages of separate networks
- PVC and SVC
- Transmission over the physical medium
- Cell size
- VPI and VCI
- VP and VC switching
- Adaptation
- Traffic contract
- ATM standards
The ATM Model
- The OSI Model
- Layers and layer functions
- The OSI model in telecommunications
- OSI services and protocols
- ATM layered reference model
- ATM protocols and the ATM model
- Physical layer
- Iub interface options
- Inverse multiplexing for ATM (IMA)
- Virtual link control
- Link failure
- Physical Medium (PM) sublayer
- Transmission Convergence (TC) sublayer
- Physical layer - SDH-based interface
- ATM operation within UMTS
- ATM cell field functions
- Payload Type (PT) field
- Cell Loss Priority (CLP) field
- Header Error Control (HEC)
- ATM Adaptation Layer (AAL)
- Convergence Sublayer (CS)
- SAR sublayer
ATM Adaptation Layers used in UMTS
- ATM in the UTRAN
- AAL2 and AAL5
- AAL2 operation
- Common Part Sublayer (CPS)
- AAL2 process
- SAR Sublayer (AAL5 SAR)
- Convergence Sublayer (AAL5 CS)
Traffic Management
- Traffic management and traffic control
- ATM service class categorization
- ITU-T and ATM Forum correlation
- ATM service category applications
- Traffic contract
- Source and connection traffic descriptors
- Operations and Maintenance (OAM)
- OAM levels
- OAM level realization
- Physical layer OAM flows
- ATM layer OAM flows, cell format and functions
ATM Application in the UTRAN
- UE Protocol Stack
- Iub and Iur interface protocol structures
- Iu interface protocol structure towards the CS domain
- Iu-PS interface protocol structure
- Radio network control plane identifiers
- The use of transport network identifiers
- Transport network control plane identifiers
- AAL2 identifiers
- GTP over IP
- Binding identifier
- ALCAP
- Services provided by ALCAP
- Functions of ALCAP
- AAL Type 2 signalling protocol
- ALCAP connection set-up
- AAL structure
- Service Specific Connection-Oriented Protoco (SSCOP)
- SSCOP PDU flow
- An example of an AAL2 signalling message delivery
- Signalling sequences that trigger ALCAP messages
- Cell set-up
- CTCH set-up
- RRC connection
- RAB establishment
- RAB release
- RNC relocation
Follow On Courses
Those involved with technologies relating to UTRAN operation should also consider the UTRAN Architectures and Protocols course or the other courses covering IP, MPLS, or SDH.
Those involved with the core network would benefit from the UMTS Core Network course, Voice over IP or the IMS and SIP course, and the other courses covering IP, MPLS, or SDH.
