Cloudifying the 3GPP IP Multimedia Subsystem for 4G and Beyond: A Survey

摘要

4G systems have been continuously evolving to cope with the emergingchallenges of human-centric and machine-to- machine (M2M) applications.Research has also now started on 5G systems. Scenarios have been proposed andinitial requirements derived. 4G and beyond systems are expected to easilydeliver a wide range of human-centric and M2M applications and services in ascalable, elastic, and cost efficient manner. The 3GPP IP multimedia subsystem(IMS) was standardized as the service delivery platform for 3G networks.Unfortunately, it does not meet several requirements for provisioningapplications and services in 4G and beyond systems. However, cloudifying itwill certainly pave the way for its use as a service delivery platform for 4Gand beyond. This article presents a critical overview of the architecturesproposed so far for cloudifying the IMS. There are two classes of approaches;the first focuses on the whole IMS system, and the second deals with specificIMS entities. Research directions are also discussed. IMS granularity and aPaaS for the development and management of IMS functional entities are the twokey directions we currently foresee.