Solving the spectrum shortage

The UK and the rest of Europe is in the midst of a spectrum dilemma. Spectrum is already scarce and there is a growing demand for LTE services over multiple input, multiple out (MIMO) networks, which is resulting in the current frequencies that are being used to accommodate these services already reaching maximum capacity.

It’s therefore not surprising that consumers have often experienced problems with the speed and reliability of their mobile connections. To make matters worse, 5G is on the horizon, which requires a significant amount more spectrum and bandwidth than many operators in the EU are currently equipped to provide.

Is spectrum farming the answer?

In response to the limited amount of spectrum, the European Union has recently proposed that EU countries release 700MHz spectrum from digital terrestrial television (DTT) services by 2020. This is often referred to as ‘spectrum farming,’ where spectrum is taken from one place and given to operators for broadband use. While this initiative is a step forward for the telecoms industry, not least because data-hungry mobile devices are increasingly permeating our everyday lives, it is important that it is shared carefully and operators make the most out of their radio waves. This can often bring about its own set of challenges.

Spectrum farming challenges

As new frequency blocks continue to proliferate (indeed, the EU began with 900MHz and 1800MHz, added 2100MHz UMTS, and more recently went to 2600MHz for LTE), mobile operators must find a solution that can seamlessly accommodate the number of different frequencies available. Radio air interface protocols have also experienced a constant churn over the years, moving from 2G to 3G to 4G, and within the next few years, to 5G.

To further complicate matters, there is a move from frequency division duplex (FDD) based systems to time division duplex (TDD) based systems, as they are inherently more efficient. Solutions deployed today must be able to handle these kind of shifts without a massive reinvestment in the infrastructure.

Many solutions deployed to meet the demand of 2G and 3G services in the past – specifically coax-based distributed antenna systems (DAS) for indoor coverage – simply can no longer accommodate these changes in mobile networks, while meeting the required or expected performance standards. Continuing to use solutions which have been in use for the past twenty years will not efficiently and economically solve the problem.

Obsolescence and upgrades

The systems that are being installed today are often obsolete on the day that they are installed, as the constant changes in wireless network technology and frequency demand new solutions on a regular basis. This has resulted in a constant cycle of system upgrades required to keep pace, which represents repetitive investment to try to solve the same problem.

In order to break the upgrade cycle and meet future wireless demands, which will be further driven by the addition of these new frequencies and protocols, a solution that is truly wideband and capable of handling virtually any new frequency or protocol, without requiring extensive and expensive equipment and accompanying infrastructure changes, is needed.

Preparing for new spectrum

In order to take full advantage of this additional spectrum from DTT services, mobile operators need to take a much smarter approach than what has been taken in the past. A good start is a truly wideband DAS (in contrast to most of today’s solutions, which use narrowband amplifiers each dedicated to a single frequency), which has the ability to seamlessly facilitate the addition of new refarmed frequencies.

This solution can accommodate any combination of services and frequencies, regardless of protocol or modulation scheme, between 150Mhz to 2700MHz on a single hardware layer, and removes the need for complex, multi-layer infrastructures. Essentially, this means that operators will be able to provide multi-service coverage efficiently and without the need to tear down their entire network infrastructure whenever a new frequency or modulation scheme is added to the mix.

Without small cell architecture that is truly wideband, operators could struggle to provide multi-service coverage without carrying out disruptive and expensive re-cabling fit-outs using single-mode optical fibre, or by installing multiple coverage solutions, each with limited spectrum or application capabilities.

A bold step

Ultimately, the wireless communications industry is continuing to evolve and putting in the groundwork for 5G will be a big focus over the next couple of years. The EU is taking the bold step towards freeing up some well-needed spectrum for DTT services, which mobile operators will likely grasp with two hands. Operators must prepare for these new frequencies now and put in place tools that will easily capitalise on the amount of spectrum available. This will be a vital part of meeting consumers’ needs now and well into the future.

John Spindler, VP of marketing and product management at Zinwave