The result of this demo showed that microwave backhaul over traditional bands can support the continued build-out of high-performing 5G networks and enhanced mobile broadband services from urban to suburban and rural areas – one of the key challenges facing communications service providers in scaling up their 5G deployment.
“We deliver fast mobile 5G connections to millions of customers across Germany. Bringing digitalisation to suburban and rural areas through mobile connectivity and fast 5G network rollout has therefore priority for us,” says Aysenur Senyer, director of transport networks at O2 Telefónica.
“Together with our partner Ericsson, we are pioneering new powerful microwave solutions using Carrier Aggregation and MIMO technology to backhaul 5G traffic over long distances in rural areas, when fibre is not an option. This type of technology enables us to deliver fibre-like connectivity via microwave and further accelerate our 5G deployment.”
Ricardo Queirós, head of microwave systems, business area networks, Ericsson, says: “Access to high-speed mobile services is key to bridging the digital divide. This joint demo with O2 Telefónica in Germany demonstrates how microwave backhaul can efficiently spread high-performing 5G to regions outside the traditional dense urban areas.”
“Wireless backhaul has been instrumental to the success of mobile networks and their nationwide coverage. Now it is time to push the boundaries and evolve microwave transmission technology to enable high-performance 5G coverage on a much broader scale,” Queirós adds.
The shift to working from home during the Covid-19 pandemic illustrated the need for fast and reliable connectivity in non-urban environments, and the challenge has been to maintain telecom-grade availability beyond distances of two to three kilometers.
The ability to deliver such high data speeds over distances of more than 10 km – the cruising altitude of a commercial jet – opens up a new world of possibilities for the delivery of low-latency, reliable broadband in harder-to-reach areas.
Traditionally, such areas have been difficult to service, as high capacities require broad bandwidths that usually only have been available in millimeter wave frequency bands (E-band). The E-band is more impacted by rain compared to the lower frequency bands, which makes it more difficult to deliver consistent service over long distances during adverse weather conditions.
Technical details
In the joint demo with O2 Telefónica in Germany, the key innovation is the ability to use MIMO with high modulation in the 112MHz channels (commercial MIMO solutions support up to 56 MHz channels), which were combined with Carrier Aggregation to enable similar capacities to E-band in the lower frequency bands. The demo solution has extended the hop-length with extremely high capacity even in less favorable weather conditions.
The backhaul link utilised the 18GHz frequency band, dual antennas in a MIMO configuration, and commercial MINI-LINK radios together with a pre-commercial baseband algorithm that allowed the use of MIMO in 2x 112 MHz channels. MIMO ensures the efficient use of limited spectrum resources. The same capacity without MIMO would demand a 448 MHz bandwidth in a cross-polar setup.
Microwave backhaul is commonly seen as a more cost- and time-efficient option compared to fibre deployment. The O2 Telefónica demo has shown that high availability and high capacity can also be achieved with wireless transport.
The demo is the latest in a series of collaborations with O2 Telefónica in Germany stretching back over several years. Ericsson is one of the service provider’s main suppliers in all areas of microwave technology and the two companies have carried out several joint projects around microwave technology, with more planned for the future.
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