IETE TECHNICAL REVIEW, Vol 23, No 4, 2006

This era marked the beginning of full-fledged huge revenue generating multimedia Internet applications and e-commerce.
However, with the huge worldwide increase in the number of mobile users each day and with emerging demands like totally user-centric services, high speed streaming Internet multimedia services (telemedicine, tele-geoprocessing, virtual navigation and VoIP), seamless global roaming with ubiquitous coverage and unhampered QoS support, 3G systems have started showing their limitations with bandwidth availability, spectrum allocation, air interference standards and lack of seamless transport mechanisms between different networks. Moreover, different short range communication systems like WLAN, Bluetooth and HIPERLAN as well as broadcast communication systems with different features spanned during this time each with its own merits and demerits targeting different types of users and different service types [2] making the situation more complicated for 3G systems.

b. Migration to the Future

These limitations and drawbacks have generated the requirement for an universal framework encompassing all the existing heterogeneous wired and wireless systems in use. This IPv6-based potential 4G framework, commonly described as MAGIC [3] (Mobile multimedia, Anytime anywhere access, Global mobility support, Integrated wireless solution and Customized personal service), would be highly

dynamic and significantly handle the limitations of 3G systems. So, consolidated solutions that can seamlessly operate on the multiple, diverse networks migrating to the 4G environment fulfilling the plethora of nextgeneration dream visualizations on implementing a transparent open wireless architecture (OWA), should be imperatively designed. This obviously invites new challenges on every step and researchers worldwide face an uphill task of designing suitable solutions. Figure 1, shows such a 4G vision.

This paper is divided into four sections: introduction, overview of the potential research challenges, highlighted research challenges and conclusions. We have identified a whole lot of probable 4G research challenges and have grouped them under
four research areas: mobile terminals and users, mobile and wireless access networks, mobile services, and communication challenges.

2.OVERVIEW OF THE POTENTIAL RESEARCH CHALLENGES

The different potential challenges are summarized in Table 1. Section 3 discusses in details on few of the highlighted research challenge areas. Table 2 represents the abbreviation used in this article.