By Shahar Peleg, director of product management at Siklu
With operators already struggling to meet the growing demand for data-rich content, the challenges they face in provisioning for the next expected escalation in traffic have never been greater.
A key bottleneck in the provision of bandwidth within the network ecosystem has traditionally been the backhaul; operators that don't already have this on their agenda need to make plans to ensure that they can accommodate this explosion of additional traffic without eroding profits.
In Europe, microwave is still the dominant wireless backhaul solution used by operators. However, this suffers from a number of limitations – spectrum licensing is costly, it has limited channel size and is becoming increasingly congested.
In highly populated European urban areas, for example, limited availability across the 6-38 GHz frequency spectrum will be further stressed by 4G and LTE sites.
Alternatives such as copper and fibre have their own drawbacks – copper is limited in capacity and reach, while fibre is often prohibitively expensive to deploy.
It is clear that the current transport networks will simply not be sufficient to enable next generation services and new approaches are required to enable operators to meet the explosion of demand, without jeopardising any increase in revenue from data traffic.
One approach that is opening up new possibilities for operators is the millimetre wave spectrum.
In this spectrum, which is found in the 3-300 GHz range, wireless systems can use the significantly larger allocated spectrum and channels to deliver multi-gigabit data rates at a much lower cost.
In Europe, use of the newly allocated and relatively under-utilised E-Band spectrum, which operates on the 71-76 GHz and 81-86 GHz spectrum, can help to ease the spectrum congestion that has started to become particularly acute in the most highly populated urban areas due to the high use of the traditional microwave bands.
E-band also offers some clear technological and economic advantages. The added benefit is that the spectrum licensing is simpler and quicker and the costs are typically significantly lower than within traditional frequencies, allowing easier frequency planning and site acquisition.
This is welcome news as the shift towards 4G/LTE is driving further changes to the network ecosystem. To exacerbate the backhaul challenge, many large operators are now investing in strategies for small cell deployments to alleviate congestion, particularly in urban areas.
For these dense deployments, operators will need both the small cells and the associated backhaul network to be as inexpensive and cost-effective as possible.
If, as we expect, small cell deployments continue to be a key focus in the next few years they must be supported by a backhaul network that is optimised for a high capacity, short range links which can be installed at the street side level.
The unlicensed 57-66 GHz frequency band provides numerous advantages for this small cell wireless backhaul. Use of this license-exempt frequency band not only saves spectrum costs but can also result in very low cost, ultra-small form factor, high-capacity wireless backhaul products, designed for quick and simple installation in street level locations, which will be a significant issue in the mass deployment of small cells.
For European operators already scrambling to accommodate current demand, there is a real and growing impetus to re-evaluate current backhaul strategies and technologies, and consider approaches that can deliver the next generation services whilst protecting profit margins.
Millimetre waves, E-band and the 57-66 GHz band, should play a significant role.