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 soloutions 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 realtime. Within mobility management we will look at Mobile-IP, GSM and GPRS, as well as mobility handled at call7session layer or at service layer via SIP, IN or via dynamic service discovery combined with SIP.

D) We will look at context-based services like: "call nearest emergency center" (via 113/112/911), "Call nearest pizza-restaurant from teh company OddPizze" (via 80013579), "show alternative screens, incl. wall mounted screens when someone dials me for video" (etc.). The technical solutions will be discussed and compared regarding scalability, business models, openness and 3rd party development etc.

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 realtime 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.

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 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

• Exercises
• Project work

Recommended previous knowledge

Courses TTM4100 Communication - Services and Networks, TTM4105 Access and Transport Networks or equivalent knowledge. The students should 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, (latest ed.) and other material such as RFCs, tutorials and papers

Credit reductions