wiley ims multimediaa telephony over cellular systems apr

[...]... legacy circuit switched system IMS Fixed Mobile MGw PSTN xDSL MGw Cable WLAN WiMAX GSM EDGE UMTS LTE Figure 1.1: Fixed–mobile convergence with IMS as the platform that enables communication regardless of access type and regardless of whether the users have subscriptions with the same or different operators 1.2 IMS and the IMS Multimedia Telephony Service The IMS Multimedia Telephony service is seen as... limited coverage, bulky terminals and high cost The potentials of mobile communications were better exploited with the digital second generation Global System for Mobile communication (GSM) that provides circuit switched connections to carry low bit rate coded speech or data The GSM systems have enjoyed enormous market response due to the highly portable terminals, thanks IMS Multimedia Telephony over Cellular. .. The development of the Integrated Service Digital Network (ISDN) provisioned different services, speech telephony, video telephony and data, over the same interface of a single network Intelligent networking provided enhancement to basic services and cellular systems added the freedom from desktop telephony Needless to say, these innovations have also been strong stimulants for industrial growth The... 7 IMS Security Mechanisms 6.3.1 Identities 6.3.2 Source Authentication of SIP Signaling 6.3.3 Authentication and Authorization 6.3.4 IMS Signaling Security 6.3.5 Security Aspects of Policy Enforcement in IMS Outlook 6.4.1 Fixed–Mobile Convergence 6.4.2 Media Security 6.4.3 Spam over IP Telephony. .. bounds I wondered, even if these predictions are valid, would voice communications take a back seat? It did not The basic need for telephony got tremendous support from cellular systems due to the offered mobility, portability, good voice quality and wide coverage Mobile telephony has reached the pinnacle of consumer items, with both grace and utility The concept of a converged network has been on the... Telephony over Cellular Systems c 2007 John Wiley & Sons, Ltd S Chakraborty, T Frankkila, J Peisa and P Synnergren 2 CHAPTER 1 INTRODUCTION to component miniaturization and improved battery technology, a voice quality that matches closely the quality of PSTN, reduced cost due to scale-factor cost benefits and rapidly expanding coverage These attributes have transformed cellular mobile systems from business... voice, commonly known as Voice over IP (VoIP) The explosion of the Internet into the consumer market has also influenced the cellular systems While GSM provided data communications over fixed rate circuit switched links at 9.6 kbps, packet services with higher data rate capabilities are increasingly offered This is reflected in such enhancements of the second generation GSM systems as General Packet Radio... and the efficient performance the CS service After redesigning the air interface, it was time to redesign the basic telephony application – to replace the voice telephony with Multimedia Telephony I hope the reader can appreciate both the flexibility and the efficiency of the IMS Multimedia Telephony xvi PREFACE Per Synnergren During my rather brief career in telecommunications I have had the pleasure... a voice service running over IP and Internet Soon companies with Internet telephony as their main business sprung up and released products based on some of the ideas developed during this time frame For some of the companies the timing was excellent and today we see the success of the IP and Internet telephony business For me as for many others, it was obvious that IP-based telephony was going to be... be big business and the discussions about fixed–mobile convergence started to gain momentum IMS was the new thing everyone talked about! IMS had been specified in 3GPP release 5 and the first releases of the important base specifications were developed during the time period of 2001–02 However, IMS lacked services IMS was built to be a general service platform that in theory didn’t need any standardization . w0 h0" alt=""