Course content

A) Architecture and principles for establishment and control of calls (sessions) and related services like SMS and IM (Instant Messaging).

B) Including fixed network (PSTN), circuit switched mobile network (GSM) and IN (intelligent networks). A particular emphesis will be put on SIP.
We will compare and discuss different system solutions described by IETF and 3PGG (in their IMS IP Multimedia Subsystem). We will present a common framework where all these system variations can be described.

C) We will put emphasis on various mobility concepts and how they differ with regards to real-time. Within mobility management we will look at Mobile-IP, GSM and GPRS, as well as mobility handled at call/session/service layer via SIP, IN or via dynamic service discovery combined with SIP.

D) We will look at context-based services like:
i) "call nearest emergency center" (via 113/112/911); ii) "Call nearest pizza-restaurant from the company OddPizza" (via 80013579); iii) "Locate or call a nearby taxi"
Technical solutions for such services will be discussed regarding nettwork centric solutions, endpoint centric solutions or socalled apps.
Requirements and wishes for spesific business models, openness towards 3rd party development, reliability/dependability of the service may all
impact the solutions. The various actors may also have conflicting interests.

E) We will discuss challenges and possible success factors when developping a "new generation" of a phone system (or ICT-solution in general), when at the same time the users are using an "old generation" of a similar system or an other ICT system based
on another technology. Nettwork externalities and flexibility / extension over time are some important aspects.

Learning outcome

A. Knowledge:

1) To get knowledge about the different (logical) functions required to establish a multimedia phone call/session with mobility and with personal context dependent behavious (such as treatment on busy, do not disturb etc.).
2) To get knowledge on how the various functional entities can be distributed among endpoints, access networks, core network and service network and which properties the different choices entail. Includes profound knowledge on the realisation in PSTN, IN, GSM, IMS.
3) Knowledge on the logical separation between signalling network and transport network (control plane and user plane).
4) Profound knowledge of SIP (Session Initiation protocol), including mechanism to handle packet loss and error situations and the interplay between SIP as a signalling protocol and media protocols like RTP. KNowledge on SIP used for instant messaging (IM).
5) Profound knowledge of how SIP is used in IETF and in IMS(3GPP), including in particular differences between endpoint centric solutions and network centric solutions.
6) Knowledge on how mobility can be handled at different layers, including knowledge on mobility in GSM, GPRS and Mobile-IP, as well as their properties for real-time services.
7) Basic knowledge on human and social factors which may impact which choices the system may take automatically, and which choices the human user should be involved in.
8) Knowledge on processes in standardization work, and factors that impact standards work and deployment of a "new generation" of a (telephony) system.

B. Skills:
1) Be able to communicate and reason about properties with different existing system solutions (such as GSM, IMS, PSTN+IN,..)
2) Be able to design, implement and evaluate properties in new system solutions for services and mobility both within big public networks, and in systems for the enterprise market.
3) actical skills in Wiresdhark (on IP), setup of a small SIP system (including ENUM), and some programming to tailor a solution for one customer or customer group by using open source for SIP.

Learning methods and activities

Lectures, practical lab work and exercises with optional deliveries (partly based on problem based learning). There is one mandatory semester assignment (with practical lab work) consisting of written report, program code and oral presentation/demonstration. The semester assignment is not graded, but will prove itself useful on the examination day. If there is a re-sit examination, the examination form may be changed from written to oral.

Compulsory assignments

• Project work

Recommended previous knowledge

TTM4100 Communication - Services and Networks and TTM4105 Access and Transport Networks, or equivalent. The students should also know from before or study in parallel the topics from TTM4115 Engineering Distributed Real-time Systems.

Course materials

Mikka Poikselka, et al.: "The IMS - IP Multimedia Concepts and Services", Wiley, (3rd. ed.) and other material such as RFCs, tutorials and papers

Credit reductions