In an industry characterised by constant evolution and revolution, striving for breakthroughs in wireless performance is simply not enough. To stay afloat, operators need to plot a path to monetisation, extracting value from not just the underlying network infrastructure, but also from the ecosystem of services that run atop that infrastructure.
This conundrum is rife at the dawn of 5G, a wireless generation that will require markedly increased capital expenditure amidst stagnant revenues. The untimely convergence of the latter has provoked an atmosphere of ambivalence to descend upon mobile operators in the face of mid-band and mmWave 5G.
While a loophole has yet to be identified, a growing number of operators and vendors have pivoted to cultivating a crop of use cases and applications designed to exploit the performance characteristics of 5G. In doing so, the common goal is to avoid succumbing to a perennial threat – becoming dumb data pipes.
CBRS sets a new performance frontier for 4G LTE and 5G NR
The diverse performance characteristics of the frequency bands deployed for 5G will dictate which applications are suitable for each operator-defined criterion. This relationship of applicability should take every conceivable aspect of performance into account, beyond merely coverage and capacity.
As an increasingly important portion of shared mid-band spectrum in the US market, the CBRS band exhibits a multitude of favourable performance attributes. Most importantly, perhaps, is the ability to exploit a frequency band with wider channel bandwidth, dramatically augmenting network capacity.
This capacity uplift can be further increased when the CBRS band is aggregated with non-contiguous 4G LTE high-bands (1800, 2100, 2600 MHz, etc.). In fact, mobile operators across the world have already leveraged the dual connectivity mode (EN-DC) of non-standalone 5G to realise capacity gains with 3.5 GHz.
Higher path loss with CBRS means it is not considered to be a “coverage band”, a role that will instead be fulfilled by low-bands including 600 and 700 MHz. Nonetheless, advancements are being made in techniques such as beamforming, enabling mobile operators to compensate for the higher path loss.
Taking the above coverage factors into account, it is important to understand that the CBRS band will be deployed in an overlay macrocell deployment atop the existing high-band 4G LTE site grid. For an LTE-based deployment of CBRS, the ability to co-locate on a large proportion of sites provides compelling cost and time efficiencies.
Beyond wide-area coverage, mobile operators will find comfort in the fact that the CBRS band is uniquely suitable for densification efforts which incorporate small cells. Localised low-cost coverage and capacity can be achieved in dense environments thanks to aggressive spectrum re-use in low-power operation with scalable bandwidth.
The Case for CBRS and Fixed Wireless Access
The aforementioned performance attributes of CBRS make it a prime medium in which to deploy Fixed Wireless Access (FWA) services. Most importantly, this frequency band enables operators to deploy massive amounts of capacity in a cost-efficient manner, wielding the potential to bridge the digital divide in underserved rural areas.
Enhanced Mobile Broadband (eMBB) represents a foundational pillar of 5G, and this plays directly into Fixed Wireless Access. In fact, the 3GPP has been working to facilitate eMBB through its release of specifications, focusing on what matters most with broadband – high peak and sustained data rates, huge capacity and a low cost per bit.
To better understand why there is a compulsion to combine CBRS with Fixed Wireless Access, a relateable example is required. Imagine a fixed fibre operator wants to expand its footprint beyond the peripherals of existing infrastructure without incurring significant capital expenditure. With CBRS, the fibre can be, in effect, extended wirelessly.
This use-case of CBRS is transformative for fixed operators, and it enables them to deem previously overlooked premises as viable for commercial deployment with Fixed Wireless Access. Not only does it open the door to more prospective broadband customers, but also to bundling with dual and triple-play offerings in more premises.
For mobile-centric operators who lack fixed infrastructure, the beauty of Fixed Wireless Access in the CBRS band is that it enables them to build out a wireless broadband network very rapidly and cost-effectivity. This acts as a form of service diversification, and it is a well-defined path to revenue growth for operators.
Conclusion: A New Era for Wireless Broadband
At the beginning of the path to 5G networks with a next-generation standalone architecture, latency enhancements will be negligible. This has provoked operators to instead concentrate on developing applications that exploit increases in network capacity and peak data rates.
Armed with frequency bands spanning an unprecedented breadth of the spectrum and rapidly increasing network density, operators can deliver a high-quality broadband experience with Fixed Wireless Access. Not only can this tackle the digital divide, but it can also provide new revenue opportunities for both fixed and mobile operators.
The CBRS band is uniquely suited to fulfilling the requirements of Fixed Wireless Access. As prime mid-band spectrum, it can be co-located on existing sites, aggregated with other non-contiguous LTE bands and offers favourable channel bandwidth. The cherry on the cake of CBRS is the fact that it is a shared frequency band.