We are currently in a transformational time for cellular connectivity, and the future of ubiquitous wireless is emerging. Worldwide successes in 2G and 3G have driven cell phone use to an incredible 6.8 billion mobile devices. This makes mobile devices almost as numerous as the world’s population. As we look to the next decade, wireless infrastructure will become even more pervasive and even more integrated with every aspect of our everyday lives. Furthermore, the future of wireless is inextricably linked with IT demand and infrastructure (and vice versa); hence the special edition of this magazine that deals with this topic.
“The next decade, wireless infrastructure will become even more pervasive and even more integrated with every aspect of our everyday lives”
Until today, the change in cellular networks from 1st to 2nd, 3rd and now 4th generation has been accompanied by a modification of the key underlying air interface technology. As we look to the future, it is very likely that there will be new signal processing technologies, but the most fundamental change will be in deployment models, integration of multiple standards and usage scenarios. We can already see this today, as traditional macro-cellular networks are augmented by smaller cells and innovative enterprise cellular deployments from both existing manufacturers and newer entrants. Enterprise cellular is analogous to enterprise Wi-Fi in a number of aspects, but it has the potential to have an even more profound impact due to the ubiquity of cellular connectivity, the quality-of-service, and inherent security that is afforded. This trend has emerged with small cell and heterogeneous networks, but will be dramatically accelerated by new, virtualized deployment models.
One new deployment concept is that of a Centralized Radio Access Network (CRAN), where signal processing for multiple cellular base stations is centralized in a single location rather than being distributed next to the antennas. This has a tremendous advantage in operating expenditure (OPEX) costs; it reduces costly truck roll-outs, mitigates power consumption, and allows load balancing to more efficiently support varying capacity demands. CRAN also provides a significant opportunity for virtualization, where general purpose computing resources can potentially be utilized for a proportion of the wireless infrastructure processing. This general purpose processing can be repurposed when capacity demands fluctuate. Moreover, the move to more of a data center-like approach encourages new providers to enter the Virtualized Radio Access Network (VRAN) space, including new manufacturers as well as wireless software providers and specialists in big data analytics.
The key enabling technologies for VRAN are likely to be General Purpose Processors and reconfigurable hardware acceleration, most notably Field Programmable Gate Arrays (FPGAs). FPGAs are often required to reduce power consumption and minimize processing load as well as to perform real-time constrained signal processing functions. The application of FPGAs in data center applications is well accepted, from their use in Microsoft’s Bing to accelerate and power reduced page ranking processing, to Intel’s announcement of a hybrid device that combines Xeon-line CPU cores with FPGAs in a single package. In the VRAN domain, Altera has the privilege to be partnered with China Mobile in the use of our FPGAs in a prototype system which was demonstrated at Mobile World Congress in March of this year.
There is a potentially powerful synergy between VRAN and Mobile Edge Computing (MEC). With MEC, applications are run closer to the edge of the network (and therefore closer to the user). This simplifies the extraction of network metadata and enables new revenue streams such as location services and edge-cloud caching. Cloud services supported on the same hardware as a VRAN have the additional advantages of (effectively) zero latency and reduced bandwidth is required to backhaul the data to the core network.
CRAN, VRAN and new heterogeneous deployment models play an important role in the evolution of 4G to 5G wireless infrastructure already under development. The demands of 5G are a series of superlatives: 100x typical end-user data rate; 100x number of connected devices; and 1,000x higher mobile data volume. In order to achieve these aggressive goals, 5G will very likely comprise some new radio technologies that focus on higher frequency bands. However, there will also be evolved deployment models and an integration of existing cellular and Wi-Fi technologies.
Elements of this vision are already being implemented in current 3GPP standardization activities for evolved LTE. For example, Unlicensed-LTE aggregates licensed and unlicensed bands in order to significantly expand link capacity. This technology coupled with multiple carrier aggregation and newer frequency bands will allow us to approach the formidable capacity goal that has been set for 5G. At the other end of the spectrum (excuse the pun), LTE Machine Type Communication (MTC) will assist lower rate device-to-device connectivity and will become a key technology of the ‘Internet-of- Things’. In writing this article, I was conscious that it rapidly becomes an alphabet soup of acronyms and a potentially confusing mix of new and emerging technologies. Therefore, to close, I want you to consider the opportunity that this plethora of technology can bring by sharing with you a specific scenario. Imagine a new building development, a mixed-usage building or campus that is built with multiple remote radio endpoints as is often done by developers to provide cellular coverage and capacity. Rather than connecting this to a traditional Distributed Antenna System (DAS) or using enterprise Wi-Fi, it can be supported by a VRAN that can load-balance WiFi, Licensed and Unlicensed LTE, and also 5G wireless processing between businesses, commercial properties and residential use. This approach of a VRAN enabled enterprise cellular system supports a wide variety of new value-added services that benefit the enterprise/residential user and provides network operators with the potential for additional revenue streams.
The use of MEC allows user (or enterprise) requirements to be more efficiently supported by localized processing or by caching popular data locally, rather than in a remote data center. At the same time, the operator can optimize the network through the extraction of user metadata, additional data on location, requested services, bandwidth demands, etc; this allows the network provider to tune service provision to maximize quality-of-service and capacity given a specific, localized scenario. A business user can use this same capability to tailor wireless connectivity to their specific requirements, across voice, data, and customized applications. In conclusion, I hope you can see that the potential for innovation in this space is tremendous. The combination of ubiquitous wireless connectivity and the support for enterprise cellular will enable a personalized and pervasive experience, tailored for each individual and business.