19
The Road Ahead
The contrast in capabilities between IMT-Advanced and its predecessor is remarkably exciting. Results from the various Evaluation Groups reporting to the ITU-R WP 5 continue to indicate that the two technologies more than satisfy the ITU-R requirements [1], which were designed to address the increasing demand for mobile traffic. To put the demand expectations into perspective, it is helpful to note that a 26-fold increase in mobile data traffic is expected by 2015, reaching a rate of 6.3 exabytes1 per month [2]. With the world population estimated to grow to a range of 7.2 to 7.5 Billion people [3], an estimate is made there will be as much as 1 mobile unit or device per capita connecting wirelessly. Estimates are also predicting that 1.3GB per month generated per smartphone, with video taking up to two thirds of the traffic. In 2020, more than 50 Billion devices will be connected to the Internet and serving a population in the range of 7.5 to 7.9 Billion – almost six devices per capita [4].
Towards this vision, the earlier deployments of IMT-Advanced would have been made, with great advancements made in both the wireless and the wired Internet. The deployments will provide substantial understanding and experience of how OFDMA operates in practice, which is currently lacking. The use of heterogeneous access networks is also projected to be the norm, with different access technologies aimed at different connection requirements. In the meantime, policies and technologies currently investigated for combating spectrum will slowly emerge, and initial large scale realizations of the adaptive and opportunistic software-defined or cognitive radios will be made. Together with these physical layer advances, especially in cooperative MIMO communication, dynamic spectrum access and allocation will open the door for higher capacity communication. It is these capacities that will make possible high bandwidth transmissions, both in the downlink and the uplink, in addition to supporting the transport of massive amounts of information. At the radio access interworking and backhaul level, advances will facilitate a more capable network-end management of network functionalities that is fitting to the multitude of devices to be communicating through the network.
At a larger scale, earlier forms of network intelligence will appear that will facilitate much desirable characteristics of network autonomy. Such characteristics include the currently deliberated aspects of self-optimization and self healing. This autonomy will depend on processing massive amount of information that will be already traversing the network, generated either by passive sensing or through active Machine-to-Machine (M2M) communications. Many of the recently starting initiatives will ensures that such processing is made in a manner that preserves the integrity and privacy of the processed information, while achieving the desired network performance and user satisfaction objectives. At the same time, operators and vendors will begin employing mechanisms for reducing energy requirements, both per-unit and for networks as a whole. Such “greener operation”, however, will not be at the cost of network reliability.
The following describes the enablers of this vision, together with the challenges faced to realize its practicality. The chapter is organized as follows. Section 19.1 discusses how IMT-Advanced network will realize reliable network capacity that fulfills the increasing user demands in a cost-efficient manner. Section 19.2 then elaborates on the access heterogeneity, and how exploiting the availability of multiple access technologies will materialize over the next ten years, especially as smarter, multiple-mode devices are introduces. The role played by cognitive radios, and impact of dynamic spectrum allocation and access will be highlighted in Section 19.3, while aspects and applications of in-network intelligence will be discussed in Section 19.4. Advances in network access infrastructure, and the importance of ever “flattening” network architectures are all discussed in Section 19.5. Meanwhile, the complexity of resource allocation, and the efforts made to combat them are discussed in Section 19.6. Finally, Section 19.7 discusses how more and more elements of IMT-Advanced networks will be “green”. The section also notes the basic tradeoffs that ground the expectations for how green IMT-Advanced networks will be.