Thanks again to Christoph K. for this new article about 3G Telephony Technology
3G systems were designed with the notion of enabling a single global standard to fulfil the needs of anywhere and anytime communication (Etoh). Compared to 2G (Second generation mobile networks, services and technologies) systems, 3G systems focus more on multimedia communication such as video conferencing and multimedia streaming. ITU (International Telecommunication Union) defined IMT-2000 as a global standard for 3G wireless communications and, within this framework, 3GPP (3rd Generation Partnership Project) developed UMTS (Universal Mobile Telecommunications System) as one of today’s 3G systems. W-CDMA (Wideband Code Division Multiple Access) is the main 3G air interface for UMTS (Holma and Toskala) implementing various person-to-person, circuit-switched services such as video telephony.
The high-level UMTS network architecture from 3GPP-R5 is described in documents from its Technical Specification Group in the figure below (Etoh).
As shown in the figure above, the UMTS core network primarily consists of a CS (Circuit-Switched) and PS (Packet-Switched) domain. Typically, the PS domain is used for end-to-end packet data applications, such as mobile Internet browsing and e-mail. On the other hand, the CS domain is intended for real-time and conversational services, such as voice and video conferencing. Circuit-switched connections are most efficient for constant, continuous data streaming by definition (Etoh). In addition to the CS and PS domains, 3GPP-R5 also specifies the IMS (IP Multimedia Subsystem).
Using the PS domain, IMS is projected to provide IP multimedia services that also satisfy real-time requirements, including those that were previously possible only in the CS domain. In this thesis, I will discuss Mobile Games over 3G Video Calling based on 3G video telephony in the CS domain (see figure above, highlighted in dark green).
By Christoph Köpernick
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